Merge branch 'master' into stress-test

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499 changed files with 14675 additions and 3145 deletions

13
.github/workflows/cancel.yml vendored Normal file
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@ -0,0 +1,13 @@
name: Cancel
on: # yamllint disable-line rule:truthy
workflow_run:
workflows: ["CIGithubActions"]
types:
- requested
jobs:
cancel:
runs-on: [self-hosted, style-checker]
steps:
- uses: styfle/cancel-workflow-action@0.9.1
with:
workflow_id: ${{ github.event.workflow.id }}

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@ -1,4 +1,4 @@
name: Ligthweight GithubActions
name: CIGithubActions
on: # yamllint disable-line rule:truthy
pull_request:
types:
@ -11,20 +11,25 @@ on: # yamllint disable-line rule:truthy
- master
jobs:
CheckLabels:
runs-on: [self-hosted]
runs-on: [self-hosted, style-checker]
steps:
- name: Check out repository code
uses: actions/checkout@v2
- name: Labels check
run: cd $GITHUB_WORKSPACE/tests/ci && python3 run_check.py
run: |
cd $GITHUB_WORKSPACE/tests/ci
python3 run_check.py
DockerHubPush:
needs: CheckLabels
runs-on: [self-hosted]
if: ${{ !contains(github.event.pull_request.labels.*.name, 'pr-documentation') && !contains(github.event.pull_request.labels.*.name, 'pr-doc-fix') }}
runs-on: [self-hosted, style-checker]
steps:
- name: Check out repository code
uses: actions/checkout@v2
- name: Images check
run: cd $GITHUB_WORKSPACE/tests/ci && python3 docker_images_check.py
run: |
cd $GITHUB_WORKSPACE/tests/ci
python3 docker_images_check.py
- name: Upload images files to artifacts
uses: actions/upload-artifact@v2
with:
@ -32,7 +37,7 @@ jobs:
path: ${{ runner.temp }}/docker_images_check/changed_images.json
StyleCheck:
needs: DockerHubPush
runs-on: [self-hosted]
runs-on: [self-hosted, style-checker]
steps:
- name: Download changed images
uses: actions/download-artifact@v2
@ -42,12 +47,82 @@ jobs:
- name: Check out repository code
uses: actions/checkout@v2
- name: Style Check
run: cd $GITHUB_WORKSPACE/tests/ci && python3 style_check.py
run: |
cd $GITHUB_WORKSPACE/tests/ci
python3 style_check.py
BuilderDebDebug:
needs: DockerHubPush
runs-on: [self-hosted, builder]
steps:
- name: Download changed images
uses: actions/download-artifact@v2
with:
name: changed_images
path: ${{ runner.temp }}/build_check
- name: Check out repository code
uses: actions/checkout@v2
with:
submodules: 'recursive'
- name: Build
env:
TEMP_PATH: ${{runner.temp}}/build_check
REPO_COPY: ${{runner.temp}}/build_check/ClickHouse
CACHES_PATH: ${{runner.temp}}/../ccaches
CHECK_NAME: 'ClickHouse build check (actions)'
BUILD_NUMBER: 7
run: |
sudo rm -fr $TEMP_PATH
mkdir -p $TEMP_PATH
cp -r $GITHUB_WORKSPACE $TEMP_PATH
cd $REPO_COPY/tests/ci && python3 build_check.py "$CHECK_NAME" $BUILD_NUMBER
- name: Upload build URLs to artifacts
uses: actions/upload-artifact@v2
with:
name: ${{ env.BUILD_NAME }}
path: ${{ runner.temp }}/build_check/${{ env.BUILD_NAME }}.json
BuilderReport:
needs: [BuilderDebDebug]
runs-on: [self-hosted, style-checker]
steps:
- name: Download json reports
uses: actions/download-artifact@v2
with:
path: ${{runner.temp}}/reports_dir
- name: Check out repository code
uses: actions/checkout@v2
- name: Report Builder
env:
TEMP_PATH: ${{runner.temp}}/report_check
REPORTS_PATH: ${{runner.temp}}/reports_dir
CHECK_NAME: 'ClickHouse build check (actions)'
run: |
sudo rm -fr $TEMP_PATH
mkdir -p $TEMP_PATH
cd $GITHUB_WORKSPACE/tests/ci
python3 build_report_check.py "$CHECK_NAME"
FastTest:
needs: DockerHubPush
runs-on: [self-hosted, builder]
steps:
- name: Check out repository code
uses: actions/checkout@v2
- name: Fast Test
env:
TEMP_PATH: ${{runner.temp}}/fasttest
REPO_COPY: ${{runner.temp}}/fasttest/ClickHouse
CACHES_PATH: ${{runner.temp}}/../ccaches
run: |
sudo rm -fr $TEMP_PATH
mkdir -p $TEMP_PATH
cp -r $GITHUB_WORKSPACE $TEMP_PATH
cd $REPO_COPY/tests/ci && python3 fast_test_check.py
FinishCheck:
needs: [StyleCheck, DockerHubPush, CheckLabels]
runs-on: [self-hosted]
needs: [StyleCheck, DockerHubPush, CheckLabels, BuilderReport, FastTest]
runs-on: [self-hosted, style-checker]
steps:
- name: Check out repository code
uses: actions/checkout@v2
- name: Finish label
run: cd $GITHUB_WORKSPACE/tests/ci && python3 finish_check.py
run: |
cd $GITHUB_WORKSPACE/tests/ci
python3 finish_check.py

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@ -149,8 +149,6 @@ if (ENABLE_FUZZING)
set (ENABLE_JEMALLOC 0)
set (ENABLE_CHECK_HEAVY_BUILDS 1)
set (GLIBC_COMPATIBILITY OFF)
set (ENABLE_PROTOBUF ON)
set (USE_INTERNAL_PROTOBUF_LIBRARY ON)
endif()
# Global libraries
@ -581,6 +579,7 @@ include (cmake/find/yaml-cpp.cmake)
include (cmake/find/s2geometry.cmake)
include (cmake/find/nlp.cmake)
include (cmake/find/bzip2.cmake)
include (cmake/find/filelog.cmake)
if(NOT USE_INTERNAL_PARQUET_LIBRARY)
set (ENABLE_ORC OFF CACHE INTERNAL "")

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@ -18,6 +18,10 @@ option (ENABLE_PCLMULQDQ "Use pclmulqdq instructions on x86_64" 1)
option (ENABLE_POPCNT "Use popcnt instructions on x86_64" 1)
option (ENABLE_AVX "Use AVX instructions on x86_64" 0)
option (ENABLE_AVX2 "Use AVX2 instructions on x86_64" 0)
option (ENABLE_AVX512 "Use AVX512 instructions on x86_64" 0)
option (ENABLE_BMI "Use BMI instructions on x86_64" 0)
option (ENABLE_AVX2_FOR_SPEC_OP "Use avx2 instructions for specific operations on x86_64" 0)
option (ENABLE_AVX512_FOR_SPEC_OP "Use avx512 instructions for specific operations on x86_64" 0)
option (ARCH_NATIVE "Add -march=native compiler flag. This makes your binaries non-portable but more performant code may be generated. This option overrides ENABLE_* options for specific instruction set. Highly not recommended to use." 0)
@ -127,6 +131,57 @@ else ()
if (HAVE_AVX2 AND ENABLE_AVX2)
set (COMPILER_FLAGS "${COMPILER_FLAGS} ${TEST_FLAG}")
endif ()
set (TEST_FLAG "-mavx512f -mavx512bw")
set (CMAKE_REQUIRED_FLAGS "${TEST_FLAG} -O0")
check_cxx_source_compiles("
#include <immintrin.h>
int main() {
auto a = _mm512_setzero_epi32();
(void)a;
auto b = _mm512_add_epi16(__m512i(), __m512i());
(void)b;
return 0;
}
" HAVE_AVX512)
if (HAVE_AVX512 AND ENABLE_AVX512)
set (COMPILER_FLAGS "${COMPILER_FLAGS} ${TEST_FLAG}")
endif ()
set (TEST_FLAG "-mbmi")
set (CMAKE_REQUIRED_FLAGS "${TEST_FLAG} -O0")
check_cxx_source_compiles("
#include <immintrin.h>
int main() {
auto a = _blsr_u32(0);
(void)a;
return 0;
}
" HAVE_BMI)
if (HAVE_BMI AND ENABLE_BMI)
set (COMPILER_FLAGS "${COMPILER_FLAGS} ${TEST_FLAG}")
endif ()
#Limit avx2/avx512 flag for specific source build
set (X86_INTRINSICS_FLAGS "")
if (ENABLE_AVX2_FOR_SPEC_OP)
if (HAVE_BMI)
set (X86_INTRINSICS_FLAGS "${X86_INTRINSICS_FLAGS} -mbmi")
endif ()
if (HAVE_AVX AND HAVE_AVX2)
set (X86_INTRINSICS_FLAGS "${X86_INTRINSICS_FLAGS} -mavx -mavx2")
endif ()
endif ()
if (ENABLE_AVX512_FOR_SPEC_OP)
set (X86_INTRINSICS_FLAGS "")
if (HAVE_BMI)
set (X86_INTRINSICS_FLAGS "${X86_INTRINSICS_FLAGS} -mbmi")
endif ()
if (HAVE_AVX512)
set (X86_INTRINSICS_FLAGS "${X86_INTRINSICS_FLAGS} -mavx512f -mavx512bw")
endif ()
endif ()
endif ()
cmake_pop_check_state ()

15
cmake/find/filelog.cmake Normal file
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@ -0,0 +1,15 @@
option (ENABLE_FILELOG "Enable FILELOG" ON)
if (NOT ENABLE_FILELOG)
message (${RECONFIGURE_MESSAGE_LEVEL} "Can't use StorageFileLog with ENABLE_FILELOG=OFF")
return()
endif()
# StorageFileLog only support Linux platform
if (OS_LINUX)
set (USE_FILELOG 1)
message (STATUS "Using StorageFileLog = 1")
else()
message(STATUS "StorageFileLog is only supported on Linux")
endif ()

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@ -8,7 +8,7 @@ endif ()
if (COMPILER_GCC)
# Require minimum version of gcc
set (GCC_MINIMUM_VERSION 10)
set (GCC_MINIMUM_VERSION 11)
if (CMAKE_CXX_COMPILER_VERSION VERSION_LESS ${GCC_MINIMUM_VERSION} AND NOT CMAKE_VERSION VERSION_LESS 2.8.9)
message (FATAL_ERROR "GCC version must be at least ${GCC_MINIMUM_VERSION}. For example, if GCC ${GCC_MINIMUM_VERSION} is available under gcc-${GCC_MINIMUM_VERSION}, g++-${GCC_MINIMUM_VERSION} names, do the following: export CC=gcc-${GCC_MINIMUM_VERSION} CXX=g++-${GCC_MINIMUM_VERSION}; rm -rf CMakeCache.txt CMakeFiles; and re run cmake or ./release.")
endif ()
@ -18,6 +18,10 @@ if (COMPILER_GCC)
elseif (COMPILER_CLANG)
# Require minimum version of clang/apple-clang
if (CMAKE_CXX_COMPILER_ID MATCHES "AppleClang")
# If you are developer you can figure out what exact versions of AppleClang are Ok,
# simply remove the following line.
message (FATAL_ERROR "AppleClang is not supported, you should install clang from brew. See the instruction: https://clickhouse.com/docs/en/development/build-osx/")
# AppleClang 10.0.1 (Xcode 10.2) corresponds to LLVM/Clang upstream version 7.0.0
# AppleClang 11.0.0 (Xcode 11.0) corresponds to LLVM/Clang upstream version 8.0.0
set (XCODE_MINIMUM_VERSION 10.2)
@ -31,7 +35,7 @@ elseif (COMPILER_CLANG)
set (CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -fchar8_t")
endif ()
else ()
set (CLANG_MINIMUM_VERSION 9)
set (CLANG_MINIMUM_VERSION 12)
if (CMAKE_CXX_COMPILER_VERSION VERSION_LESS ${CLANG_MINIMUM_VERSION})
message (FATAL_ERROR "Clang version must be at least ${CLANG_MINIMUM_VERSION}.")
endif ()

2
contrib/NuRaft vendored

@ -1 +1 @@
Subproject commit 7ecb16844af6a9c283ad432d85ecc2e7d1544676
Subproject commit d10351f312c1ae1ca3fdda433693dfbef3acfece

2
contrib/aws vendored

@ -1 +1 @@
Subproject commit 06aa8759d17f2032ffd5efa83969270ca9ac727b
Subproject commit 00b03604543367d7e310cb0993973fdcb723ea79

2
contrib/poco vendored

@ -1 +1 @@
Subproject commit 46c80daf1b015aa10474ce82e3d24b578c6ae422
Subproject commit 39fd359765a3a77b46d94ec3c5def3c7802a920f

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@ -17,6 +17,16 @@ endif ()
add_subdirectory("${protobuf_SOURCE_DIR}/cmake" "${protobuf_BINARY_DIR}")
if (ENABLE_FUZZING)
# `protoc` will be built with sanitizer and it could fail during ClickHouse build
# It easily reproduces in oss-fuzz building pipeline
# To avoid this we can try to build `protoc` without any sanitizer with option `-fno-sanitize=all`, but
# it this case we will face with linker errors, because libcxx still will be built with sanitizer
# So, we can simply suppress all of these failures with a combination this flag and an environment variable
# export MSAN_OPTIONS=exit_code=0
target_compile_options(protoc PRIVATE "-fsanitize-recover=all")
endif()
# We don't want to stop compilation on warnings in protobuf's headers.
# The following line overrides the value assigned by the command target_include_directories() in libprotobuf.cmake
set_property(TARGET libprotobuf PROPERTY INTERFACE_SYSTEM_INCLUDE_DIRECTORIES "${protobuf_SOURCE_DIR}/src")

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@ -12,19 +12,19 @@ printenv
rm -f CMakeCache.txt
read -ra CMAKE_FLAGS <<< "${CMAKE_FLAGS:-}"
# Hope, that the most part of files will be in cache, so we just link new executables
cmake --debug-trycompile --verbose=1 -DCMAKE_VERBOSE_MAKEFILE=1 -LA -DCMAKE_C_COMPILER="$CC" -DCMAKE_CXX_COMPILER="$CXX" -DENABLE_CLICKHOUSE_ODBC_BRIDGE=OFF \
-DENABLE_LIBRARIES=0 -DENABLE_SSL=1 -DUSE_INTERNAL_SSL_LIBRARY=1 -DUSE_UNWIND=ON -DENABLE_EMBEDDED_COMPILER=0 \
-DENABLE_EXAMPLES=0 -DENABLE_UTILS=0 -DENABLE_THINLTO=0 "-DSANITIZE=$SANITIZER" \
-DENABLE_FUZZING=1 -DFUZZER='libfuzzer' -DENABLE_TCMALLOC=0 -DENABLE_JEMALLOC=0 \
-DENABLE_CHECK_HEAVY_BUILDS=1 -DGLIBC_COMPATIBILITY=OFF "${CMAKE_FLAGS[@]}" ..
# Please, add or change flags directly in cmake
cmake --debug-trycompile --verbose=1 -DCMAKE_VERBOSE_MAKEFILE=1 -LA -DCMAKE_C_COMPILER="$CC" -DCMAKE_CXX_COMPILER="$CXX" \
-DSANITIZE="$SANITIZER" -DENABLE_FUZZING=1 -DFUZZER='libfuzzer' -DENABLE_PROTOBUF=1 -DUSE_INTERNAL_PROTOBUF_LIBRARY=1 "${CMAKE_FLAGS[@]}" ..
FUZZER_TARGETS=$(find ../src -name '*_fuzzer.cpp' -execdir basename {} .cpp ';' | tr '\n' ' ')
NUM_JOBS=$(($(nproc || grep -c ^processor /proc/cpuinfo)))
mkdir -p /output/fuzzers
for FUZZER_TARGET in $FUZZER_TARGETS
do
# shellcheck disable=SC2086 # No quotes because I want it to expand to nothing if empty.
ninja $NINJA_FLAGS $FUZZER_TARGET
ninja $NINJA_FLAGS $FUZZER_TARGET -j $NUM_JOBS
# Find this binary in build directory and strip it
FUZZER_PATH=$(find ./src -name "$FUZZER_TARGET")
strip --strip-unneeded "$FUZZER_PATH"

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@ -139,12 +139,17 @@ mv /var/log/clickhouse-server/stderr.log /test_output/ ||:
if [[ -n "$WITH_COVERAGE" ]] && [[ "$WITH_COVERAGE" -eq 1 ]]; then
tar -chf /test_output/clickhouse_coverage.tar.gz /profraw ||:
fi
tar -chf /test_output/text_log_dump.tar /var/lib/clickhouse/data/system/text_log ||:
tar -chf /test_output/query_log_dump.tar /var/lib/clickhouse/data/system/query_log ||:
tar -chf /test_output/zookeeper_log_dump.tar /var/lib/clickhouse/data/system/zookeeper_log ||:
tar -chf /test_output/trace_log_dump.tar /var/lib/clickhouse/data/system/trace_log ||:
tar -chf /test_output/coordination.tar /var/lib/clickhouse/coordination ||:
# Replace the engine with Ordinary to avoid extra symlinks stuff in artifacts.
# (so that clickhouse-local --path can read it w/o extra care).
sed -i -e "s/ATTACH DATABASE _ UUID '[^']*'/ATTACH DATABASE system/" -e "s/Atomic/Ordinary/" /var/lib/clickhouse/metadata/system.sql
for table in text_log query_log zookeeper_log trace_log; do
sed -i "s/ATTACH TABLE _ UUID '[^']*'/ATTACH TABLE $table/" /var/lib/clickhouse/metadata/system/${table}.sql
tar -chf /test_output/${table}_dump.tar /var/lib/clickhouse/metadata/system.sql /var/lib/clickhouse/metadata/system/${table}.sql /var/lib/clickhouse/data/system/${table} ||:
done
if [[ -n "$USE_DATABASE_REPLICATED" ]] && [[ "$USE_DATABASE_REPLICATED" -eq 1 ]]; then
grep -Fa "Fatal" /var/log/clickhouse-server/clickhouse-server1.log ||:
grep -Fa "Fatal" /var/log/clickhouse-server/clickhouse-server2.log ||:

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@ -288,8 +288,14 @@ done
tar -chf /test_output/coordination.tar /var/lib/clickhouse/coordination ||:
mv /var/log/clickhouse-server/stderr.log /test_output/
tar -chf /test_output/query_log_dump.tar /var/lib/clickhouse/data/system/query_log ||:
tar -chf /test_output/trace_log_dump.tar /var/lib/clickhouse/data/system/trace_log ||:
# Replace the engine with Ordinary to avoid extra symlinks stuff in artifacts.
# (so that clickhouse-local --path can read it w/o extra care).
sed -i -e "s/ATTACH DATABASE _ UUID '[^']*'/ATTACH DATABASE system/" -e "s/Atomic/Ordinary/" /var/lib/clickhouse/metadata/system.sql
for table in query_log trace_log; do
sed -i "s/ATTACH TABLE _ UUID '[^']*'/ATTACH TABLE $table/" /var/lib/clickhouse/metadata/system/${table}.sql
tar -chf /test_output/${table}_dump.tar /var/lib/clickhouse/metadata/system.sql /var/lib/clickhouse/metadata/system/${table}.sql /var/lib/clickhouse/data/system/${table} ||:
done
# Write check result into check_status.tsv
clickhouse-local --structure "test String, res String" -q "SELECT 'failure', test FROM table WHERE res != 'OK' order by (lower(test) like '%hung%') LIMIT 1" < /test_output/test_results.tsv > /test_output/check_status.tsv

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@ -10,7 +10,7 @@ RUN apt-get update && env DEBIAN_FRONTEND=noninteractive apt-get install --yes \
python3-pip \
pylint \
yamllint \
&& pip3 install codespell
&& pip3 install codespell PyGithub boto3 unidiff
COPY run.sh /
COPY process_style_check_result.py /

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@ -3,9 +3,15 @@ toc_priority: 65
toc_title: Build on Mac OS X
---
# You don't have to build ClickHouse
You can install ClickHouse as follows: https://clickhouse.com/#quick-start
Choose Mac x86 or M1.
# How to Build ClickHouse on Mac OS X {#how-to-build-clickhouse-on-mac-os-x}
Build should work on x86_64 (Intel) and arm64 (Apple Silicon) based macOS 10.15 (Catalina) and higher with recent Xcode's native AppleClang, or Homebrew's vanilla Clang or GCC compilers.
Build should work on x86_64 (Intel) and arm64 (Apple Silicon) based macOS 10.15 (Catalina) and higher with Homebrew's vanilla Clang.
It is always recommended to use `clang` compiler. It is possible to use XCode's `AppleClang` or `gcc` but it's strongly discouraged.
## Install Homebrew {#install-homebrew}
@ -45,18 +51,6 @@ git clone --recursive git@github.com:ClickHouse/ClickHouse.git
## Build ClickHouse {#build-clickhouse}
To build using Xcode's native AppleClang compiler:
``` bash
cd ClickHouse
rm -rf build
mkdir build
cd build
cmake -DCMAKE_BUILD_TYPE=RelWithDebInfo ..
cmake --build . --config RelWithDebInfo
cd ..
```
To build using Homebrew's vanilla Clang compiler:
``` bash
@ -69,7 +63,19 @@ cmake --build . --config RelWithDebInfo
cd ..
```
To build using Homebrew's vanilla GCC compiler:
To build using Xcode's native AppleClang compiler (this option is strongly not recommended; use the option above):
``` bash
cd ClickHouse
rm -rf build
mkdir build
cd build
cmake -DCMAKE_BUILD_TYPE=RelWithDebInfo ..
cmake --build . --config RelWithDebInfo
cd ..
```
To build using Homebrew's vanilla GCC compiler (this option is absolutely not recommended, I'm wondering why do we ever have it):
``` bash
cd ClickHouse

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@ -35,6 +35,8 @@ The [system.clusters](../../operations/system-tables/clusters.md) system table c
When creating a new replica of the database, this replica creates tables by itself. If the replica has been unavailable for a long time and has lagged behind the replication log — it checks its local metadata with the current metadata in ZooKeeper, moves the extra tables with data to a separate non-replicated database (so as not to accidentally delete anything superfluous), creates the missing tables, updates the table names if they have been renamed. The data is replicated at the `ReplicatedMergeTree` level, i.e. if the table is not replicated, the data will not be replicated (the database is responsible only for metadata).
[`ALTER TABLE ATTACH|FETCH|DROP|DROP DETACHED|DETACH PARTITION|PART`](../../sql-reference/statements/alter/partition.md) queries are allowed but not replicated. The database engine will only add/fetch/remove the partition/part to the current replica. However, if the table itself uses a Replicated table engine, then the data will be replicated after using `ATTACH`.
## Usage Example {#usage-example}
Creating a cluster with three hosts:

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@ -36,7 +36,7 @@ CREATE TABLE [IF NOT EXISTS] [db.]table_name
Create a table in ClickHouse which allows to read data from MongoDB collection:
``` text
``` sql
CREATE TABLE mongo_table
(
key UInt64,
@ -46,7 +46,7 @@ CREATE TABLE mongo_table
To read from an SSL secured MongoDB server:
``` text
``` sql
CREATE TABLE mongo_table_ssl
(
key UInt64,

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@ -5,7 +5,7 @@ toc_title: Distributed
# Distributed Table Engine {#distributed}
Tables with Distributed engine do not store any data by their own, but allow distributed query processing on multiple servers.
Tables with Distributed engine do not store any data of their own, but allow distributed query processing on multiple servers.
Reading is automatically parallelized. During a read, the table indexes on remote servers are used, if there are any.
The Distributed engine accepts parameters:
@ -167,20 +167,20 @@ If this parameter is set to `true`, the write operation selects the first health
If it is set to `false` (the default), data is written to all replicas. In essence, this means that the Distributed table replicates data itself. This is worse than using replicated tables, because the consistency of replicas is not checked, and over time they will contain slightly different data.
To select the shard that a row of data is sent to, the sharding expression is analyzed, and its remainder is taken from dividing it by the total weight of the shards. The row is sent to the shard that corresponds to the half-interval of the remainders from `prev_weight` to `prev_weights + weight`, where `prev_weights` is the total weight of the shards with the smallest number, and `weight` is the weight of this shard. For example, if there are two shards, and the first has a weight of 9 while the second has a weight of 10, the row will be sent to the first shard for the remainders from the range \[0, 9), and to the second for the remainders from the range \[9, 19).
To select the shard that a row of data is sent to, the sharding expression is analyzed, and its remainder is taken from dividing it by the total weight of the shards. The row is sent to the shard that corresponds to the half-interval of the remainders from `prev_weights` to `prev_weights + weight`, where `prev_weights` is the total weight of the shards with the smallest number, and `weight` is the weight of this shard. For example, if there are two shards, and the first has a weight of 9 while the second has a weight of 10, the row will be sent to the first shard for the remainders from the range \[0, 9), and to the second for the remainders from the range \[9, 19).
The sharding expression can be any expression from constants and table columns that returns an integer. For example, you can use the expression `rand()` for random distribution of data, or `UserID` for distribution by the remainder from dividing the users ID (then the data of a single user will reside on a single shard, which simplifies running IN and JOIN by users). If one of the columns is not distributed evenly enough, you can wrap it in a hash function: intHash64(UserID).
A simple reminder from the division is a limited solution for sharding and isnt always appropriate. It works for medium and large volumes of data (dozens of servers), but not for very large volumes of data (hundreds of servers or more). In the latter case, use the sharding scheme required by the subject area, rather than using entries in Distributed tables.
A simple remainder from the division is a limited solution for sharding and isnt always appropriate. It works for medium and large volumes of data (dozens of servers), but not for very large volumes of data (hundreds of servers or more). In the latter case, use the sharding scheme required by the subject area, rather than using entries in Distributed tables.
SELECT queries are sent to all the shards and work regardless of how data is distributed across the shards (they can be distributed completely randomly). When you add a new shard, you do not have to transfer the old data to it. You can write new data with a heavier weight the data will be distributed slightly unevenly, but queries will work correctly and efficiently.
SELECT queries are sent to all the shards and work regardless of how data is distributed across the shards (they can be distributed completely randomly). When you add a new shard, you do not have to transfer old data into it. Instead, you can write new data to it by using a heavier weight the data will be distributed slightly unevenly, but queries will work correctly and efficiently.
You should be concerned about the sharding scheme in the following cases:
- Queries are used that require joining data (IN or JOIN) by a specific key. If data is sharded by this key, you can use local IN or JOIN instead of GLOBAL IN or GLOBAL JOIN, which is much more efficient.
- A large number of servers is used (hundreds or more) with a large number of small queries (queries of individual clients - websites, advertisers, or partners). In order for the small queries to not affect the entire cluster, it makes sense to locate data for a single client on a single shard. Alternatively, as weve done in Yandex.Metrica, you can set up bi-level sharding: divide the entire cluster into “layers”, where a layer may consist of multiple shards. Data for a single client is located on a single layer, but shards can be added to a layer as necessary, and data is randomly distributed within them. Distributed tables are created for each layer, and a single shared distributed table is created for global queries.
Data is written asynchronously. When inserted in the table, the data block is just written to the local file system. The data is sent to the remote servers in the background as soon as possible. The period for sending data is managed by the [distributed_directory_monitor_sleep_time_ms](../../../operations/settings/settings.md#distributed_directory_monitor_sleep_time_ms) and [distributed_directory_monitor_max_sleep_time_ms](../../../operations/settings/settings.md#distributed_directory_monitor_max_sleep_time_ms) settings. The `Distributed` engine sends each file with inserted data separately, but you can enable batch sending of files with the [distributed_directory_monitor_batch_inserts](../../../operations/settings/settings.md#distributed_directory_monitor_batch_inserts) setting. This setting improves cluster performance by better utilizing local server and network resources. You should check whether data is sent successfully by checking the list of files (data waiting to be sent) in the table directory: `/var/lib/clickhouse/data/database/table/`. The number of threads performing background tasks can be set by [background_distributed_schedule_pool_size](../../../operations/settings/settings.md#background_distributed_schedule_pool_size) setting.
Data is written asynchronously. When inserted in the table, the data block is just written to the local file system. The data is sent to the remote servers in the background as soon as possible. The periodicity for sending data is managed by the [distributed_directory_monitor_sleep_time_ms](../../../operations/settings/settings.md#distributed_directory_monitor_sleep_time_ms) and [distributed_directory_monitor_max_sleep_time_ms](../../../operations/settings/settings.md#distributed_directory_monitor_max_sleep_time_ms) settings. The `Distributed` engine sends each file with inserted data separately, but you can enable batch sending of files with the [distributed_directory_monitor_batch_inserts](../../../operations/settings/settings.md#distributed_directory_monitor_batch_inserts) setting. This setting improves cluster performance by better utilizing local server and network resources. You should check whether data is sent successfully by checking the list of files (data waiting to be sent) in the table directory: `/var/lib/clickhouse/data/database/table/`. The number of threads performing background tasks can be set by [background_distributed_schedule_pool_size](../../../operations/settings/settings.md#background_distributed_schedule_pool_size) setting.
If the server ceased to exist or had a rough restart (for example, after a device failure) after an INSERT to a Distributed table, the inserted data might be lost. If a damaged data part is detected in the table directory, it is transferred to the `broken` subdirectory and no longer used.

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@ -27,11 +27,10 @@ It is recommended to use official pre-compiled `deb` packages for Debian or Ubun
{% include 'install/deb.sh' %}
```
You can replace `stable` with `lts` or `testing` to use different [release trains](../faq/operations/production.md) based on your needs.
You can replace `stable` with `lts` or `testing` to use different [release trains](../faq/operations/production.md) based on your needs.
You can also download and install packages manually from [here](https://repo.clickhouse.com/deb/stable/main/).
#### Packages {#packages}
- `clickhouse-common-static` — Installs ClickHouse compiled binary files.

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@ -129,6 +129,20 @@ Features:
- Support monitor (processor, connection, query)
- Support migrate data
### Bytebase {#bytebase}
[Bytebase](https://bytebase.com) is a web-based, open source schema change and version control tool for teams. It supports various databases including ClickHouse.
Features:
- Schema review between developers and DBAs.
- Database-as-Code, version control the schema in VCS such GitLab and trigger the deployment upon code commit.
- Streamlined deployment with per-environment policy.
- Full migration history.
- Schema drift detection.
- Backup and restore.
- RBAC.
## Commercial {#commercial}
### DataGrip {#datagrip}

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@ -22,10 +22,13 @@ toc_title: Adopters
| <a href="https://apiroad.net/" class="favicon">ApiRoad</a> | API marketplace | Analytics | — | — | [Blog post, Nov 2018, Mar 2020](https://pixeljets.com/blog/clickhouse-vs-elasticsearch/) |
| <a href="https://www.appsflyer.com" class="favicon">Appsflyer</a> | Mobile analytics | Main product | — | — | [Talk in Russian, July 2019](https://www.youtube.com/watch?v=M3wbRlcpBbY) |
| <a href="https://arenadata.tech/" class="favicon">ArenaData</a> | Data Platform | Main product | — | — | [Slides in Russian, December 2019](https://github.com/ClickHouse/clickhouse-presentations/blob/master/meetup38/indexes.pdf) |
| <a href="https://www.argedor.com/en/clickhouse/" class="favicon">Argedor</a> | ClickHouse support | — | — | — | [Official website](https://www.argedor.com/en/clickhouse/) |
| <a href="https://avito.ru/" class="favicon">Avito</a> | Classifieds | Monitoring | — | — | [Meetup, April 2020](https://www.youtube.com/watch?v=n1tm4j4W8ZQ) |
| <a href="https://badoo.com" class="favicon">Badoo</a> | Dating | Timeseries | — | — | [Slides in Russian, December 2019](https://presentations.clickhouse.com/meetup38/forecast.pdf) |
| <a href="https://beeline.ru/" class="favicon">Beeline</a> | Telecom | Data Platform | — | — | [Blog post, July 2021](https://habr.com/en/company/beeline/blog/567508/) |
| <a href="https://www.benocs.com/" class="favicon">Benocs</a> | Network Telemetry and Analytics | Main Product | — | — | [Slides in English, October 2017](https://github.com/ClickHouse/clickhouse-presentations/blob/master/meetup9/lpm.pdf) |
| <a href="https://www.bigo.sg/" class="favicon">BIGO</a> | Video | Computing Platform | — | — | [Blog Article, August 2020](https://www.programmersought.com/article/44544895251/) |
| <a href="https://www.bilibili.com/" class="favicon">BiliBili</a> | Video sharing | — | — | — | [Blog post, June 2021](https://chowdera.com/2021/06/20210622012241476b.html) |
| <a href="https://www.bloomberg.com/">Bloomberg</a> | Finance, Media | Monitoring | — | — | [Slides, May 2018](https://www.slideshare.net/Altinity/http-analytics-for-6m-requests-per-second-using-clickhouse-by-alexander-bocharov) |
| <a href="https://bloxy.info" class="favicon">Bloxy</a> | Blockchain | Analytics | — | — | [Slides in Russian, August 2018](https://github.com/ClickHouse/clickhouse-presentations/blob/master/meetup17/4_bloxy.pptx) |
| <a href="https://www.bytedance.com" class="favicon">Bytedance</a> | Social platforms | — | — | — | [The ClickHouse Meetup East, October 2020](https://www.youtube.com/watch?v=ckChUkC3Pns) |
@ -33,6 +36,7 @@ toc_title: Adopters
| <a href="https://carto.com/" class="favicon">CARTO</a> | Business Intelligence | Geo analytics | — | — | [Geospatial processing with ClickHouse](https://carto.com/blog/geospatial-processing-with-clickhouse/) |
| <a href="http://public.web.cern.ch/public/" class="favicon">CERN</a> | Research | Experiment | — | — | [Press release, April 2012](https://www.yandex.com/company/press_center/press_releases/2012/2012-04-10/) |
| <a href="https://www.checklyhq.com/" class="favicon">Checkly</a> | Software Development | Analytics | — | — | [Tweet, October 2021](https://twitter.com/tim_nolet/status/1445810665743081474?s=20) |
| <a href="https://chelpipegroup.com/" class="favicon">ChelPipe Group</a> | Analytics | — | — | — | [Blog post, June 2021](https://vc.ru/trade/253172-tyazhelomu-proizvodstvu-user-friendly-sayt-internet-magazin-trub-dlya-chtpz) |
| <a href="http://cisco.com/" class="favicon">Cisco</a> | Networking | Traffic analysis | — | — | [Lightning talk, October 2019](https://youtu.be/-hI1vDR2oPY?t=5057) |
| <a href="https://www.citadelsecurities.com/" class="favicon">Citadel Securities</a> | Finance | — | — | — | [Contribution, March 2019](https://github.com/ClickHouse/ClickHouse/pull/4774) |
| <a href="https://city-mobil.ru" class="favicon">Citymobil</a> | Taxi | Analytics | — | — | [Blog Post in Russian, March 2020](https://habr.com/en/company/citymobil/blog/490660/) |
@ -48,6 +52,7 @@ toc_title: Adopters
| <a href="https://db.com" class="favicon">Deutsche Bank</a> | Finance | BI Analytics | — | — | [Slides in English, October 2019](https://bigdatadays.ru/wp-content/uploads/2019/10/D2-H3-3_Yakunin-Goihburg.pdf) |
| <a href="https://deeplay.io/eng/" class="favicon">Deeplay</a> | Gaming Analytics | — | — | — | [Job advertisement, 2020](https://career.habr.com/vacancies/1000062568) |
| <a href="https://www.diva-e.com" class="favicon">Diva-e</a> | Digital consulting | Main Product | — | — | [Slides in English, September 2019](https://github.com/ClickHouse/clickhouse-presentations/blob/master/meetup29/ClickHouse-MeetUp-Unusual-Applications-sd-2019-09-17.pdf) |
| <a href="https://ecommpay.com/" class="favicon">Ecommpay</a> | Payment Processing | Logs | — | — | [Video, Nov 2019](https://www.youtube.com/watch?v=d3GdZTOWGLk) |
| <a href="https://www.ecwid.com/" class="favicon">Ecwid</a> | E-commerce SaaS | Metrics, Logging | — | — | [Slides in Russian, April 2019](https://nastachku.ru/var/files/1/presentation/backend/2_Backend_6.pdf) |
| <a href="https://www.ebay.com/" class="favicon">eBay</a> | E-commerce | Logs, Metrics and Events | — | — | [Official website, Sep 2020](https://tech.ebayinc.com/engineering/ou-online-analytical-processing/) |
| <a href="https://www.exness.com/" class="favicon">Exness</a> | Trading | Metrics, Logging | — | — | [Talk in Russian, May 2019](https://youtu.be/_rpU-TvSfZ8?t=3215) |
@ -57,9 +62,11 @@ toc_title: Adopters
| <a href="https://fun.co/rp" class="favicon">FunCorp</a> | Games | | — | 14 bn records/day as of Jan 2021 | [Article](https://www.altinity.com/blog/migrating-from-redshift-to-clickhouse) |
| <a href="https://geniee.co.jp" class="favicon">Geniee</a> | Ad network | Main product | — | — | [Blog post in Japanese, July 2017](https://tech.geniee.co.jp/entry/2017/07/20/160100) |
| <a href="https://www.genotek.ru/" class="favicon">Genotek</a> | Bioinformatics | Main product | — | — | [Video, August 2020](https://youtu.be/v3KyZbz9lEE) |
| <a href="https://gigapipe.com/" class="favicon">Gigapipe</a> | Managed ClickHouse | Main product | — | — | [Official website](https://gigapipe.com/) |
| <a href="https://glaber.io/" class="favicon">Glaber</a> | Monitoring | Main product | — | — | [Website](https://glaber.io/) |
| <a href="https://graphcdn.io/" class="favicon">GraphCDN</a> | CDN | Traffic Analytics | — | — | [Blog Post in English, August 2021](https://altinity.com/blog/delivering-insight-on-graphql-apis-with-clickhouse-at-graphcdn/) |
| <a href="https://www.huya.com/" class="favicon">HUYA</a> | Video Streaming | Analytics | — | — | [Slides in Chinese, October 2018](https://github.com/ClickHouse/clickhouse-presentations/blob/master/meetup19/7.%20ClickHouse万亿数据分析实践%20李本旺(sundy-li)%20虎牙.pdf) |
| <a href="https://www.hydrolix.io/" class="favicon">Hydrolix</a> | Cloud data platform | Main product | — | — | [Documentation](https://docs.hydrolix.io/guide/query) |
| <a href="https://www.the-ica.com/" class="favicon">ICA</a> | FinTech | Risk Management | — | — | [Blog Post in English, Sep 2020](https://altinity.com/blog/clickhouse-vs-redshift-performance-for-fintech-risk-management?utm_campaign=ClickHouse%20vs%20RedShift&utm_content=143520807&utm_medium=social&utm_source=twitter&hss_channel=tw-3894792263) |
| <a href="https://www.idealista.com" class="favicon">Idealista</a> | Real Estate | Analytics | — | — | [Blog Post in English, April 2019](https://clickhouse.com/blog/en/clickhouse-meetup-in-madrid-on-april-2-2019) |
| <a href="https://infobaleen.com" class="favicon">Infobaleen</a> | AI markting tool | Analytics | — | — | [Official site](https://infobaleen.com) |
@ -71,9 +78,11 @@ toc_title: Adopters
| <a href="https://ippon.tech" class="favicon">Ippon Technologies</a> | Technology Consulting | — | — | — | [Talk in English, July 2020](https://youtu.be/GMiXCMFDMow?t=205) |
| <a href="https://www.ivi.ru/" class="favicon">Ivi</a> | Online Cinema | Analytics, Monitoring | — | — | [Article in Russian, Jan 2018](https://habr.com/en/company/ivi/blog/347408/) |
| <a href="https://jinshuju.net" class="favicon">Jinshuju 金数据</a> | BI Analytics | Main product | — | — | [Slides in Chinese, October 2019](https://github.com/ClickHouse/clickhouse-presentations/blob/master/meetup24/3.%20金数据数据架构调整方案Public.pdf) |
| <a href="https://www.kakaocorp.com/" class="favicon">kakaocorp</a> | Internet company | — | — | — | [if(kakao)2020 conference](https://if.kakao.com/session/117) |
| <a href="https://www.kodiakdata.com/" class="favicon">Kodiak Data</a> | Clouds | Main product | — | — | [Slides in Engish, April 2018](https://github.com/ClickHouse/clickhouse-presentations/blob/master/meetup13/kodiak_data.pdf) |
| <a href="https://kontur.ru" class="favicon">Kontur</a> | Software Development | Metrics | — | — | [Talk in Russian, November 2018](https://www.youtube.com/watch?v=U4u4Bd0FtrY) |
| <a href="https://www.kuaishou.com/" class="favicon">Kuaishou</a> | Video | — | — | — | [ClickHouse Meetup, October 2018](https://clickhouse.com/blog/en/2018/clickhouse-community-meetup-in-beijing-on-october-28-2018/) |
| <a href="https://www.kgk-global.com/en/" class="favicon">KGK Global</a> | Vehicle monitoring | — | — | — | [Press release, June 2021](https://zoom.cnews.ru/news/item/530921) |
| <a href="https://www.lbl.gov" class="favicon">Lawrence Berkeley National Laboratory</a> | Research | Traffic analysis | 1 server | 11.8 TiB | [Slides in English, April 2019](https://www.smitasin.com/presentations/2019-04-17_DOE-NSM.pdf) |
| <a href="https://lifestreet.com/" class="favicon">LifeStreet</a> | Ad network | Main product | 75 servers (3 replicas) | 5.27 PiB | [Blog post in Russian, February 2017](https://habr.com/en/post/322620/) |
| <a href="https://mcs.mail.ru/" class="favicon">Mail.ru Cloud Solutions</a> | Cloud services | Main product | — | — | [Article in Russian](https://mcs.mail.ru/help/db-create/clickhouse#) |
@ -88,7 +97,10 @@ toc_title: Adopters
| <a href="https://www.netskope.com/" class="favicon">Netskope</a> | Network Security | — | — | — | [Job advertisement, March 2021](https://www.mendeley.com/careers/job/senior-software-developer-backend-developer-1346348) |
| <a href="https://niclabs.cl/" class="favicon">NIC Labs</a> | Network Monitoring | RaTA-DNS | — | — | [Blog post, March 2021](https://niclabs.cl/ratadns/2021/03/Clickhouse) |
| <a href="https://getnoc.com/" class="favicon">NOC Project</a> | Network Monitoring | Analytics | Main Product | — | [Official Website](https://getnoc.com/features/big-data/) |
| <a href="https://www.noction.com" class="favicon">Noction</a> | Network Technology | Main Product | — | — | [Official Website](https://www.noction.com/news/irp-3-11-remote-triggered-blackholing-capability)
| <a href="https://www.nuna.com/" class="favicon">Nuna Inc.</a> | Health Data Analytics | — | — | — | [Talk in English, July 2020](https://youtu.be/GMiXCMFDMow?t=170) |
| <a href="https://ok.ru" class="favicon">Ok.ru</a> | Social Network | — | 72 servers | 810 TB compressed, 50bn rows/day, 1.5 TB/day | [SmartData conference, Oct 2021](https://assets.ctfassets.net/oxjq45e8ilak/4JPHkbJenLgZhBGGyyonFP/57472ec6987003ec4078d0941740703b/____________________ClickHouse_______________________.pdf) |
| <a href="https://omnicomm.ru/" class="favicon">Omnicomm</a> | Transportation Monitoring | — | — | — | [Facebook post, Oct 2021](https://www.facebook.com/OmnicommTeam/posts/2824479777774500) |
| <a href="https://www.oneapm.com/" class="favicon">OneAPM</a> | Monitorings and Data Analysis | Main product | — | — | [Slides in Chinese, October 2018](https://github.com/ClickHouse/clickhouse-presentations/blob/master/meetup19/8.%20clickhouse在OneAPM的应用%20杜龙.pdf) |
| <a href="https://corp.ozon.com/" class="favicon">OZON</a> | E-commerce | — | — | — | [Official website](https://job.ozon.ru/vacancy/razrabotchik-clickhouse-ekspluatatsiya-40991870/) |
| <a href="https://panelbear.com/" class="favicon">Panelbear | Analytics | Monitoring and Analytics | — | — | [Tech Stack, November 2020](https://panelbear.com/blog/tech-stack/) |
@ -103,6 +115,7 @@ toc_title: Adopters
| <a href="https://qrator.net" class="favicon">Qrator</a> | DDoS protection | Main product | — | — | [Blog Post, March 2019](https://blog.qrator.net/en/clickhouse-ddos-mitigation_37/) |
| <a href="https://www.rbinternational.com/" class="favicon">Raiffeisenbank</a> | Banking | Analytics | — | — | [Lecture in Russian, December 2020](https://cs.hse.ru/announcements/421965599.html) |
| <a href="https://rambler.ru" class="favicon">Rambler</a> | Internet services | Analytics | — | — | [Talk in Russian, April 2018](https://medium.com/@ramblertop/разработка-api-clickhouse-для-рамблер-топ-100-f4c7e56f3141) |
| <a href="https://replicahq.com" class="favicon">Replica</a> | Urban Planning | Analytics | — | — | [Job advertisement](https://boards.greenhouse.io/replica/jobs/5547732002?gh_jid=5547732002) |
| <a href="https://retell.cc/" class="favicon">Retell</a> | Speech synthesis | Analytics | — | — | [Blog Article, August 2020](https://vc.ru/services/153732-kak-sozdat-audiostati-na-vashem-sayte-i-zachem-eto-nuzhno) |
| <a href="https://www.rollbar.com" class="favicon">Rollbar</a> | Software Development | Main Product | — | — | [Official Website](https://www.rollbar.com) |
| <a href="https://rspamd.com/" class="favicon">Rspamd</a> | Antispam | Analytics | — | — | [Official Website](https://rspamd.com/doc/modules/clickhouse.html) |
@ -116,6 +129,7 @@ toc_title: Adopters
| <a href="https://sentry.io/" class="favicon">Sentry</a> | Software Development | Main product | — | — | [Blog Post in English, May 2019](https://blog.sentry.io/2019/05/16/introducing-snuba-sentrys-new-search-infrastructure) |
| <a href="https://seo.do/" class="favicon">seo.do</a> | Analytics | Main product | — | — | [Slides in English, November 2019](https://github.com/ClickHouse/clickhouse-presentations/blob/master/meetup35/CH%20Presentation-%20Metehan%20Çetinkaya.pdf) |
| <a href="http://www.sgk.gov.tr/wps/portal/sgk/tr" class="favicon">SGK</a> | Government Social Security | Analytics | — | — | [Slides in English, November 2019](https://github.com/ClickHouse/clickhouse-presentations/blob/master/meetup35/ClickHouse%20Meetup-Ramazan%20POLAT.pdf) |
| <a href="https://signoz.io/" class="favicon">SigNoz</a> | Observability Platform | Main Product | — | — | [Source code](https://github.com/SigNoz/signoz) |
| <a href="http://english.sina.com/index.html" class="favicon">Sina</a> | News | — | — | — | [Slides in Chinese, October 2018](https://github.com/ClickHouse/clickhouse-presentations/blob/master/meetup19/6.%20ClickHouse最佳实践%20高鹏_新浪.pdf) |
| <a href="https://www.sipfront.com/" class="favicon">Sipfront</a> | Software Development | Analytics | — | — | [Tweet, October 2021](https://twitter.com/andreasgranig/status/1446404332337913895?s=20) |
| <a href="https://smi2.ru/" class="favicon">SMI2</a> | News | Analytics | — | — | [Blog Post in Russian, November 2017](https://habr.com/ru/company/smi2/blog/314558/) |
@ -129,12 +143,14 @@ toc_title: Adopters
| <a href="https://www.tencent.com" class="favicon">Tencent</a> | Big Data | Data processing | — | — | [Slides in Chinese, October 2018](https://github.com/ClickHouse/clickhouse-presentations/blob/master/meetup19/5.%20ClickHouse大数据集群应用_李俊飞腾讯网媒事业部.pdf) |
| <a href="https://www.tencent.com" class="favicon">Tencent</a> | Messaging | Logging | — | — | [Talk in Chinese, November 2019](https://youtu.be/T-iVQRuw-QY?t=5050) |
| <a href="https://www.tencentmusic.com/" class="favicon">Tencent Music Entertainment (TME)</a> | BigData | Data processing | — | — | [Blog in Chinese, June 2020](https://cloud.tencent.com/developer/article/1637840) |
| <a href="https://www.tesla.com/" class="favicon">Tesla</a> | Electric vehicle and clean energy company | — | — | — | [Vacancy description, March 2021](https://news.ycombinator.com/item?id=26306170) |
| <a href="https://timeflow.systems" class="favicon">Timeflow</a> | Software | Analytics | — | — | [Blog](https://timeflow.systems/why-we-moved-from-druid-to-clickhouse/ ) |
| <a href="https://www.tinybird.co/" class="favicon">Tinybird</a> | Real-time Data Products | Data processing | — | — | [Official website](https://www.tinybird.co/) |
| <a href="https://trafficstars.com/" class="favicon">Traffic Stars</a> | AD network | — | — | — | [Slides in Russian, May 2018](https://github.com/ClickHouse/clickhouse-presentations/blob/master/meetup15/lightning/ninja.pdf) |
| <a href="https://trafficstars.com/" class="favicon">Traffic Stars</a> | AD network | — | 300 servers in Europe/US | 1.8 PiB, 700 000 insert rps (as of 2021) | [Slides in Russian, May 2018](https://github.com/ClickHouse/clickhouse-presentations/blob/master/meetup15/lightning/ninja.pdf) |
| <a href="https://www.uber.com" class="favicon">Uber</a> | Taxi | Logging | — | — | [Slides, February 2020](https://presentations.clickhouse.com/meetup40/uber.pdf) |
| <a href="https://hello.utmstat.com/" class="favicon">UTMSTAT</a> | Analytics | Main product | — | — | [Blog post, June 2020](https://vc.ru/tribuna/133956-striming-dannyh-iz-servisa-skvoznoy-analitiki-v-clickhouse) |
| <a href="https://vk.com" class="favicon">VKontakte</a> | Social Network | Statistics, Logging | — | — | [Slides in Russian, August 2018](https://github.com/ClickHouse/clickhouse-presentations/blob/master/meetup17/3_vk.pdf) |
| <a href="https://www.vmware.com/" class="favicon">VMWare</a> | Cloud | VeloCloud, SDN | — | — | [Product documentation](https://docs.vmware.com/en/vRealize-Operations-Manager/8.3/com.vmware.vcom.metrics.doc/GUID-A9AD72E1-C948-4CA2-971B-919385AB3CA8.html) |
| <a href="https://www.vmware.com/" class="favicon">VMware</a> | Cloud | VeloCloud, SDN | — | — | [Product documentation](https://docs.vmware.com/en/vRealize-Operations-Manager/8.3/com.vmware.vcom.metrics.doc/GUID-A9AD72E1-C948-4CA2-971B-919385AB3CA8.html) |
| <a href="https://www.walmartlabs.com/" class="favicon">Walmart Labs</a> | Internet, Retail | — | — | — | [Talk in English, July 2020](https://youtu.be/GMiXCMFDMow?t=144) |
| <a href="https://wargaming.com/en/" class="favicon">Wargaming</a> | Games | | — | — | [Interview](https://habr.com/en/post/496954/) |
| <a href="https://www.wildberries.ru/" class="favicon">Wildberries</a> | E-commerce | | — | — | [Official website](https://it.wildberries.ru/) |
@ -148,24 +164,11 @@ toc_title: Adopters
| <a href="https://market.yandex.ru/" class="favicon">Yandex Market</a> | e-Commerce | Metrics, Logging | — | — | [Talk in Russian, January 2019](https://youtu.be/_l1qP0DyBcA?t=478) |
| <a href="https://metrica.yandex.com" class="favicon">Yandex Metrica</a> | Web analytics | Main product | 630 servers in one cluster, 360 servers in another cluster, 1862 servers in one department | 133 PiB / 8.31 PiB / 120 trillion records | [Slides, February 2020](https://presentations.clickhouse.com/meetup40/introduction/#13) |
| <a href="https://www.yotascale.com/" class="favicon">Yotascale</a> | Cloud | Data pipeline | — | 2 bn records/day | [LinkedIn (Accomplishments)](https://www.linkedin.com/in/adilsaleem/) |
| <a href="https://zagravagames.com/en/" class="favicon">Zagrava Trading</a> | — | — | — | — | [Job offer, May 2021](https://twitter.com/datastackjobs/status/1394707267082063874) |
| <a href="https://htc-cs.ru/" class="favicon">ЦВТ</a> | Software Development | Metrics, Logging | — | — | [Blog Post, March 2019, in Russian](https://vc.ru/dev/62715-kak-my-stroili-monitoring-na-prometheus-clickhouse-i-elk) |
| <a href="https://mkb.ru/" class="favicon">МКБ</a> | Bank | Web-system monitoring | — | — | [Slides in Russian, September 2019](https://github.com/ClickHouse/clickhouse-presentations/blob/master/meetup28/mkb.pdf) |
| <a href="https://cft.ru/" class="favicon">ЦФТ</a> | Banking, Financial products, Payments | — | — | — | [Meetup in Russian, April 2020](https://team.cft.ru/events/162) |
| <a href="https://promo.croc.ru/digitalworker" class="favicon">Цифровой Рабочий</a> | Industrial IoT, Analytics | — | — | — | [Blog post in Russian, March 2021](https://habr.com/en/company/croc/blog/548018/) |
| <a href="https://www.kakaocorp.com/" class="favicon">kakaocorp</a> | Internet company | — | — | — | [if(kakao)2020 conference](https://if.kakao.com/session/117) |
| <a href="https://shop.okraina.ru/" class="favicon">ООО «МПЗ Богородский»</a> | Agriculture | — | — | — | [Article in Russian, November 2020](https://cloud.yandex.ru/cases/okraina) |
| <a href="https://www.tesla.com/" class="favicon">Tesla</a> | Electric vehicle and clean energy company | — | — | — | [Vacancy description, March 2021](https://news.ycombinator.com/item?id=26306170) |
| <a href="https://www.kgk-global.com/en/" class="favicon">KGK Global</a> | Vehicle monitoring | — | — | — | [Press release, June 2021](https://zoom.cnews.ru/news/item/530921) |
| <a href="https://www.bilibili.com/" class="favicon">BiliBili</a> | Video sharing | — | — | — | [Blog post, June 2021](https://chowdera.com/2021/06/20210622012241476b.html) |
| <a href="https://gigapipe.com/" class="favicon">Gigapipe</a> | Managed ClickHouse | Main product | — | — | [Official website](https://gigapipe.com/) |
| <a href="https://www.hydrolix.io/" class="favicon">Hydrolix</a> | Cloud data platform | Main product | — | — | [Documentation](https://docs.hydrolix.io/guide/query) |
| <a href="https://www.argedor.com/en/clickhouse/" class="favicon">Argedor</a> | ClickHouse support | — | — | — | [Official website](https://www.argedor.com/en/clickhouse/) |
| <a href="https://signoz.io/" class="favicon">SigNoz</a> | Observability Platform | Main Product | — | — | [Source code](https://github.com/SigNoz/signoz) |
| <a href="https://chelpipegroup.com/" class="favicon">ChelPipe Group</a> | Analytics | — | — | — | [Blog post, June 2021](https://vc.ru/trade/253172-tyazhelomu-proizvodstvu-user-friendly-sayt-internet-magazin-trub-dlya-chtpz) |
| <a href="https://zagravagames.com/en/" class="favicon">Zagrava Trading</a> | — | — | — | — | [Job offer, May 2021](https://twitter.com/datastackjobs/status/1394707267082063874) |
| <a href="https://beeline.ru/" class="favicon">Beeline</a> | Telecom | Data Platform | — | — | [Blog post, July 2021](https://habr.com/en/company/beeline/blog/567508/) |
| <a href="https://ecommpay.com/" class="favicon">Ecommpay</a> | Payment Processing | Logs | — | — | [Video, Nov 2019](https://www.youtube.com/watch?v=d3GdZTOWGLk) |
| <a href="https://omnicomm.ru/" class="favicon">Omnicomm</a> | Transportation Monitoring | — | — | — | [Facebook post, Oct 2021](https://www.facebook.com/OmnicommTeam/posts/2824479777774500) |
| <a href="https://ok.ru" class="favicon">Ok.ru</a> | Social Network | — | 72 servers | 810 TB compressed, 50bn rows/day, 1.5 TB/day | [SmartData conference, Oct 2021](https://assets.ctfassets.net/oxjq45e8ilak/4JPHkbJenLgZhBGGyyonFP/57472ec6987003ec4078d0941740703b/____________________ClickHouse_______________________.pdf) |
[Original article](https://clickhouse.com/docs/en/introduction/adopters/) <!--hide-->

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@ -643,7 +643,7 @@ On hosts with low RAM and swap, you possibly need setting `max_server_memory_usa
## max_concurrent_queries {#max-concurrent-queries}
The maximum number of simultaneously processed queries related to MergeTree table. Queries may be limited by other settings: [max_concurrent_queries_for_all_users](#max-concurrent-queries-for-all-users), [min_marks_to_honor_max_concurrent_queries](#min-marks-to-honor-max-concurrent-queries).
The maximum number of simultaneously processed queries related to MergeTree table. Queries may be limited by other settings: [max_concurrent_queries_for_user](#max-concurrent-queries-for-user), [max_concurrent_queries_for_all_users](#max-concurrent-queries-for-all-users), [min_marks_to_honor_max_concurrent_queries](#min-marks-to-honor-max-concurrent-queries).
!!! info "Note"
These settings can be modified at runtime and will take effect immediately. Queries that are already running will remain unchanged.
@ -659,6 +659,21 @@ Possible values:
<max_concurrent_queries>100</max_concurrent_queries>
```
## max_concurrent_queries_for_user {#max-concurrent-queries-for-user}
The maximum number of simultaneously processed queries related to MergeTree table per user.
Possible values:
- Positive integer.
- 0 — Disabled.
**Example**
``` xml
<max_concurrent_queries_for_user>5</max_concurrent_queries_for_user>
```
## max_concurrent_queries_for_all_users {#max-concurrent-queries-for-all-users}
Throw exception if the value of this setting is less or equal than the current number of simultaneously processed queries.

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@ -1788,15 +1788,31 @@ Default value: 0
## distributed_push_down_limit (#distributed-push-down-limit}
LIMIT will be applied on each shard separatelly. Usually you don't need to use it, since this will be done automatically if it is possible, i.e. for simple query SELECT FROM LIMIT.
LIMIT will be applied on each shard separatelly.
This will allow to avoid:
- sending extra rows over network,
- processing rows behind the limit on the initiator.
It is possible if at least one of the following conditions met:
- `distributed_group_by_no_merge` > 0
- query **does not have `GROUP BY`/`DISTINCT`/`LIMIT BY`**, but it has `ORDER BY`/`LIMIT`.
- query **has `GROUP BY`/`DISTINCT`/`LIMIT BY`** with `ORDER BY`/`LIMIT` and:
- `optimize_skip_unused_shards_limit` is enabled
- `optimize_distributed_group_by_sharding_key` is enabled
Possible values:
- 0 - Disabled
- 1 - Enabled
!!! note "Note"
That with this setting the result of the query may be inaccurate.
See also:
- [distributed_group_by_no_merge](#distributed-group-by-no-merge)
- [optimize_skip_unused_shards](#optimize-skip-unused-shards)
- [optimize_distributed_group_by_sharding_key](#optimize-distributed-group-by-sharding-key)
## optimize_skip_unused_shards_limit {#optimize-skip-unused-shards-limit}
@ -3814,3 +3830,86 @@ Default value: `0`.
**See Also**
- [optimize_move_to_prewhere](#optimize_move_to_prewhere) setting
## async_insert {#async-insert}
Enables or disables asynchronous inserts. This makes sense only for insertion over HTTP protocol. Note that deduplication isn't working for such inserts.
If enabled, the data is combined into batches before the insertion into tables, so it is possible to do small and frequent insertions into ClickHouse (up to 15000 queries per second) without buffer tables.
The data is inserted either after the [async_insert_max_data_size](#async-insert-max-data-size) is exceeded or after [async_insert_busy_timeout_ms](#async-insert-busy-timeout-ms) milliseconds since the first `INSERT` query. If the [async_insert_stale_timeout_ms](#async-insert-stale-timeout-ms) is set to a non-zero value, the data is inserted after `async_insert_stale_timeout_ms` milliseconds since the last query.
If [wait_for_async_insert](#wait-for-async-insert) is enabled, every client will wait for the data to be processed and flushed to the table. Otherwise, the query would be processed almost instantly, even if the data is not inserted.
Possible values:
- 0 — Insertions are made synchronously, one after another.
- 1 — Multiple asynchronous insertions enabled.
Default value: `0`.
## async_insert_threads {#async-insert-threads}
The maximum number of threads for background data parsing and insertion.
Possible values:
- Positive integer.
- 0 — Asynchronous insertions are disabled.
Default value: `16`.
## wait_for_async_insert {#wait-for-async-insert}
Enables or disables waiting for processing of asynchronous insertion. If enabled, server will return `OK` only after the data is inserted. Otherwise, it will return `OK` even if the data wasn't inserted.
Possible values:
- 0 — Server returns `OK` even if the data is not yet inserted.
- 1 — Server returns `OK` only after the data is inserted.
Default value: `1`.
## wait_for_async_insert_timeout {#wait-for-async-insert-timeout}
The timeout in seconds for waiting for processing of asynchronous insertion.
Possible values:
- Positive integer.
- 0 — Disabled.
Default value: [lock_acquire_timeout](#lock_acquire_timeout).
## async_insert_max_data_size {#async-insert-max-data-size}
The maximum size of the unparsed data in bytes collected per query before being inserted.
Possible values:
- Positive integer.
- 0 — Asynchronous insertions are disabled.
Default value: `1000000`.
## async_insert_busy_timeout_ms {#async-insert-busy-timeout-ms}
The maximum timeout in milliseconds since the first `INSERT` query before inserting collected data.
Possible values:
- Positive integer.
- 0 — Timeout disabled.
Default value: `200`.
## async_insert_stale_timeout_ms {#async-insert-stale-timeout-ms}
The maximum timeout in milliseconds since the last `INSERT` query before dumping collected data. If enabled, the settings prolongs the [async_insert_busy_timeout_ms](#async-insert-busy-timeout-ms) with every `INSERT` query as long as [async_insert_max_data_size](#async-insert-max-data-size) is not exceeded.
Possible values:
- Positive integer.
- 0 — Timeout disabled.
Default value: `0`.

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@ -70,7 +70,7 @@ For HDD, enable the write cache.
## File System {#file-system}
Ext4 is the most reliable option. Set the mount options `noatime, nobarrier`.
Ext4 is the most reliable option. Set the mount options `noatime`.
XFS is also suitable, but it hasnt been as thoroughly tested with ClickHouse.
Most other file systems should also work fine. File systems with delayed allocation work better.

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@ -0,0 +1,43 @@
---
toc_priority: 302
---
# entropy {#entropy}
Calculates [Shannon entropy](https://en.wikipedia.org/wiki/Entropy_(information_theory)) of a column of values.
**Syntax**
``` sql
entropy(val)
```
**Arguments**
- `val` — Column of values of any type.
**Returned value**
- Shannon entropy.
Type: [Float64](../../../sql-reference/data-types/float.md).
**Example**
Query:
``` sql
CREATE TABLE entropy (`vals` UInt32,`strings` String) ENGINE = Memory;
INSERT INTO entropy VALUES (1, 'A'), (1, 'A'), (1,'A'), (1,'A'), (2,'B'), (2,'B'), (2,'C'), (2,'D');
SELECT entropy(vals), entropy(strings) FROM entropy;
```
Result:
``` text
┌─entropy(vals)─┬─entropy(strings)─┐
│ 1 │ 1.75 │
└───────────────┴──────────────────┘
```

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@ -53,15 +53,17 @@ LAYOUT(LAYOUT_TYPE(param value)) -- layout settings
- [flat](#flat)
- [hashed](#dicts-external_dicts_dict_layout-hashed)
- [sparse_hashed](#dicts-external_dicts_dict_layout-sparse_hashed)
- [cache](#cache)
- [ssd_cache](#ssd-cache)
- [direct](#direct)
- [range_hashed](#range-hashed)
- [complex_key_hashed](#complex-key-hashed)
- [complex_key_sparse_hashed](#complex-key-sparse-hashed)
- [hashed_array](#dicts-external_dicts_dict_layout-hashed-array)
- [complex_key_hashed_array](#complex-key-hashed-array)
- [range_hashed](#range-hashed)
- [complex_key_range_hashed](#complex-key-range-hashed)
- [cache](#cache)
- [complex_key_cache](#complex-key-cache)
- [ssd_cache](#ssd-cache)
- [ssd_complex_key_cache](#complex-key-ssd-cache)
- [complex_key_ssd_cache](#complex-key-ssd-cache)
- [direct](#direct)
- [complex_key_direct](#complex-key-direct)
- [ip_trie](#ip-trie)
@ -151,13 +153,15 @@ Configuration example:
</layout>
```
or
``` sql
LAYOUT(COMPLEX_KEY_HASHED())
```
### complex_key_sparse_hashed {#complex-key-sparse-hashed}
This type of storage is for use with composite [keys](../../../sql-reference/dictionaries/external-dictionaries/external-dicts-dict-structure.md). Similar to `sparse_hashed`.
This type of storage is for use with composite [keys](../../../sql-reference/dictionaries/external-dictionaries/external-dicts-dict-structure.md). Similar to [sparse_hashed](#dicts-external_dicts_dict_layout-sparse_hashed).
Configuration example:
@ -167,13 +171,15 @@ Configuration example:
</layout>
```
or
``` sql
LAYOUT(COMPLEX_KEY_SPARSE_HASHED())
```
### hashed_array {#dicts-external_dicts_dict_layout-hashed-array}
The dictionary is completely stored in memory. Each attribute is stored in array. Key attribute is stored in the form of hashed table where value is index in attributes array. The dictionary can contain any number of elements with any identifiers In practice, the number of keys can reach tens of millions of items.
The dictionary is completely stored in memory. Each attribute is stored in an array. The key attribute is stored in the form of a hashed table where value is an index in the attributes array. The dictionary can contain any number of elements with any identifiers. In practice, the number of keys can reach tens of millions of items.
All types of sources are supported. When updating, data (from a file or from a table) is read in its entirety.
@ -194,7 +200,7 @@ LAYOUT(HASHED_ARRAY())
### complex_key_hashed_array {#complex-key-hashed-array}
This type of storage is for use with composite [keys](../../../sql-reference/dictionaries/external-dictionaries/external-dicts-dict-structure.md). Similar to `hashed_array`.
This type of storage is for use with composite [keys](../../../sql-reference/dictionaries/external-dictionaries/external-dicts-dict-structure.md). Similar to [hashed_array](#dicts-external_dicts_dict_layout-hashed-array).
Configuration example:
@ -204,11 +210,12 @@ Configuration example:
</layout>
```
or
``` sql
LAYOUT(COMPLEX_KEY_HASHED_ARRAY())
```
### range_hashed {#range-hashed}
The dictionary is stored in memory in the form of a hash table with an ordered array of ranges and their corresponding values.
@ -356,8 +363,9 @@ When searching for a dictionary, the cache is searched first. For each block of
If keys are not found in dictionary, then update cache task is created and added into update queue. Update queue properties can be controlled with settings `max_update_queue_size`, `update_queue_push_timeout_milliseconds`, `query_wait_timeout_milliseconds`, `max_threads_for_updates`.
For cache dictionaries, the expiration [lifetime](../../../sql-reference/dictionaries/external-dictionaries/external-dicts-dict-lifetime.md) of data in the cache can be set. If more time than `lifetime` has passed since loading the data in a cell, the cells value is not used and key becomes expired, and it is re-requested the next time it needs to be used this behaviour can be configured with setting `allow_read_expired_keys`.
This is the least effective of all the ways to store dictionaries. The speed of the cache depends strongly on correct settings and the usage scenario. A cache type dictionary performs well only when the hit rates are high enough (recommended 99% and higher). You can view the average hit rate in the `system.dictionaries` table.
For cache dictionaries, the expiration [lifetime](../../../sql-reference/dictionaries/external-dictionaries/external-dicts-dict-lifetime.md) of data in the cache can be set. If more time than `lifetime` has passed since loading the data in a cell, the cells value is not used and key becomes expired. The key is re-requested the next time it needs to be used. This behaviour can be configured with setting `allow_read_expired_keys`.
This is the least effective of all the ways to store dictionaries. The speed of the cache depends strongly on correct settings and the usage scenario. A cache type dictionary performs well only when the hit rates are high enough (recommended 99% and higher). You can view the average hit rate in the [system.dictionaries](../../../operations/system-tables/dictionaries.md) table.
If setting `allow_read_expired_keys` is set to 1, by default 0. Then dictionary can support asynchronous updates. If a client requests keys and all of them are in cache, but some of them are expired, then dictionary will return expired keys for a client and request them asynchronously from the source.
@ -545,4 +553,3 @@ dictGetString('prefix', 'asn', tuple(IPv6StringToNum('2001:db8::1')))
Other types are not supported yet. The function returns the attribute for the prefix that corresponds to this IP address. If there are overlapping prefixes, the most specific one is returned.
Data must completely fit into RAM.

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@ -82,3 +82,76 @@ An exception is thrown when dividing by zero or when dividing a minimal negative
Returns the least common multiple of the numbers.
An exception is thrown when dividing by zero or when dividing a minimal negative number by minus one.
## max2 {#max2}
Compares two values and returns the maximum. The returned value is converted to [Float64](../../sql-reference/data-types/float.md).
**Syntax**
```sql
max2(value1, value2)
```
**Arguments**
- `value1` — First value. [Int/UInt](../../sql-reference/data-types/int-uint.md) or [Float](../../sql-reference/data-types/float.md).
- `value2` — Second value. [Int/UInt](../../sql-reference/data-types/int-uint.md) or [Float](../../sql-reference/data-types/float.md).
**Returned value**
- The maximum of two values.
Type: [Float](../../sql-reference/data-types/float.md).
**Example**
Query:
```sql
SELECT max2(-1, 2);
```
Result:
```text
┌─max2(-1, 2)─┐
│ 2 │
└─────────────┘
```
## min2 {#min2}
Compares two values and returns the minimum. The returned value is converted to [Float64](../../sql-reference/data-types/float.md).
**Syntax**
```sql
max2(value1, value2)
```
**Arguments**
- `value1` — First value. [Int/UInt](../../sql-reference/data-types/int-uint.md) or [Float](../../sql-reference/data-types/float.md).
- `value2` — Second value. [Int/UInt](../../sql-reference/data-types/int-uint.md) or [Float](../../sql-reference/data-types/float.md).
**Returned value**
- The minimum of two values.
Type: [Float](../../sql-reference/data-types/float.md).
**Example**
Query:
```sql
SELECT min2(-1, 2);
```
Result:
```text
┌─min2(-1, 2)─┐
│ -1 │
└─────────────┘
```

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@ -306,6 +306,77 @@ Result:
└───────────────────────────────────────────────────────────────────────────────────────────────────────┘
```
## JSON_EXISTS(json, path) {#json-exists}
If the value exists in the JSON document, `1` will be returned.
If the value does not exist, `0` will be returned.
Examples:
``` sql
SELECT JSON_EXISTS('{"hello":1}', '$.hello');
SELECT JSON_EXISTS('{"hello":{"world":1}}', '$.hello.world');
SELECT JSON_EXISTS('{"hello":["world"]}', '$.hello[*]');
SELECT JSON_EXISTS('{"hello":["world"]}', '$.hello[0]');
```
!!! note "Note"
before version 21.11 the order of arguments was wrong, i.e. JSON_EXISTS(path, json)
## JSON_QUERY(json, path) {#json-query}
Parses a JSON and extract a value as JSON array or JSON object.
If the value does not exist, an empty string will be returned.
Example:
``` sql
SELECT JSON_QUERY('{"hello":"world"}', '$.hello');
SELECT JSON_QUERY('{"array":[[0, 1, 2, 3, 4, 5], [0, -1, -2, -3, -4, -5]]}', '$.array[*][0 to 2, 4]');
SELECT JSON_QUERY('{"hello":2}', '$.hello');
SELECT toTypeName(JSON_QUERY('{"hello":2}', '$.hello'));
```
Result:
``` text
["world"]
[0, 1, 4, 0, -1, -4]
[2]
String
```
!!! note "Note"
before version 21.11 the order of arguments was wrong, i.e. JSON_QUERY(path, json)
## JSON_VALUE(json, path) {#json-value}
Parses a JSON and extract a value as JSON scalar.
If the value does not exist, an empty string will be returned.
Example:
``` sql
SELECT JSON_VALUE('{"hello":"world"}', '$.hello');
SELECT JSON_VALUE('{"array":[[0, 1, 2, 3, 4, 5], [0, -1, -2, -3, -4, -5]]}', '$.array[*][0 to 2, 4]');
SELECT JSON_VALUE('{"hello":2}', '$.hello');
SELECT toTypeName(JSON_VALUE('{"hello":2}', '$.hello'));
```
Result:
``` text
"world"
0
2
String
```
!!! note "Note"
before version 21.11 the order of arguments was wrong, i.e. JSON_VALUE(path, json)
## toJSONString {#tojsonstring}
Serializes a value to its JSON representation. Various data types and nested structures are supported.

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@ -2427,3 +2427,39 @@ Type: [UInt32](../../sql-reference/data-types/int-uint.md).
**See Also**
- [shardNum()](#shard-num) function example also contains `shardCount()` function call.
## getOSKernelVersion {#getoskernelversion}
Returns a string with the current OS kernel version.
**Syntax**
``` sql
getOSKernelVersion()
```
**Arguments**
- None.
**Returned value**
- The current OS kernel version.
Type: [String](../../sql-reference/data-types/string.md).
**Example**
Query:
``` sql
SELECT getOSKernelVersion();
```
Result:
``` text
┌─getOSKernelVersion()────┐
│ Linux 4.15.0-55-generic │
└─────────────────────────┘
```

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@ -213,7 +213,7 @@ SELECT splitByNonAlpha(' 1! a, b. ');
## arrayStringConcat(arr\[, separator\]) {#arraystringconcatarr-separator}
Concatenates the strings listed in the array with the separator.separator is an optional parameter: a constant string, set to an empty string by default.
Concatenates the strings (values of type String or Nullable(String)) listed in the array with the separator. separator is an optional parameter: a constant string, set to an empty string by default.
Returns the string.
## alphaTokens(s) {#alphatokenss}
@ -270,3 +270,40 @@ Result:
│ [['abc','123'],['8','"hkl"']] │
└───────────────────────────────────────────────────────────────────────┘
```
## ngrams {#ngrams}
Splits the UTF-8 string into n-grams of `ngramsize` symbols.
**Syntax**
``` sql
ngrams(string, ngramsize)
```
**Arguments**
- `string` — String. [String](../../sql-reference/data-types/string.md) or [FixedString](../../sql-reference/data-types/fixedstring.md).
- `ngramsize` — The size of an n-gram. [UInt](../../sql-reference/data-types/int-uint.md).
**Returned values**
- Array with n-grams.
Type: [Array](../../sql-reference/data-types/array.md)([FixedString](../../sql-reference/data-types/fixedstring.md)).
**Example**
Query:
``` sql
SELECT ngrams('ClickHouse', 3);
```
Result:
``` text
┌─ngrams('ClickHouse', 3)───────────────────────────┐
│ ['Cli','lic','ick','ckH','kHo','Hou','ous','use'] │
└───────────────────────────────────────────────────┘
```

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@ -165,3 +165,805 @@ Result:
│ 2 │
└─────────────────┘
```
## tuplePlus {#tupleplus}
Calculates the sum of corresponding values of two tuples of the same size.
**Syntax**
```sql
tuplePlus(tuple1, tuple2)
```
Alias: `vectorSum`.
**Arguments**
- `tuple1` — First tuple. [Tuple](../../sql-reference/data-types/tuple.md).
- `tuple2` — Second tuple. [Tuple](../../sql-reference/data-types/tuple.md).
**Returned value**
- Tuple with the sum.
Type: [Tuple](../../sql-reference/data-types/tuple.md).
**Example**
Query:
```sql
SELECT tuplePlus((1, 2), (2, 3));
```
Result:
```text
┌─tuplePlus((1, 2), (2, 3))─┐
│ (3,5) │
└───────────────────────────┘
```
## tupleMinus {#tupleminus}
Calculates the subtraction of corresponding values of two tuples of the same size.
**Syntax**
```sql
tupleMinus(tuple1, tuple2)
```
Alias: `vectorDifference`.
**Arguments**
- `tuple1` — First tuple. [Tuple](../../sql-reference/data-types/tuple.md).
- `tuple2` — Second tuple. [Tuple](../../sql-reference/data-types/tuple.md).
**Returned value**
- Tuple with the result of subtraction.
Type: [Tuple](../../sql-reference/data-types/tuple.md).
**Example**
Query:
```sql
SELECT tupleMinus((1, 2), (2, 3));
```
Result:
```text
┌─tupleMinus((1, 2), (2, 3))─┐
│ (-1,-1) │
└────────────────────────────┘
```
## tupleMultiply {#tuplemultiply}
Calculates the multiplication of corresponding values of two tuples of the same size.
**Syntax**
```sql
tupleMultiply(tuple1, tuple2)
```
**Arguments**
- `tuple1` — First tuple. [Tuple](../../sql-reference/data-types/tuple.md).
- `tuple2` — Second tuple. [Tuple](../../sql-reference/data-types/tuple.md).
**Returned value**
- Tuple with the multiplication.
Type: [Tuple](../../sql-reference/data-types/tuple.md).
**Example**
Query:
```sql
SELECT tupleMultiply((1, 2), (2, 3));
```
Result:
```text
┌─tupleMultiply((1, 2), (2, 3))─┐
│ (2,6) │
└───────────────────────────────┘
```
## tupleDivide {#tupledivide}
Calculates the division of corresponding values of two tuples of the same size. Note that division by zero will return `inf`.
**Syntax**
```sql
tupleDivide(tuple1, tuple2)
```
**Arguments**
- `tuple1` — First tuple. [Tuple](../../sql-reference/data-types/tuple.md).
- `tuple2` — Second tuple. [Tuple](../../sql-reference/data-types/tuple.md).
**Returned value**
- Tuple with the result of division.
Type: [Tuple](../../sql-reference/data-types/tuple.md).
**Example**
Query:
```sql
SELECT tupleDivide((1, 2), (2, 3));
```
Result:
```text
┌─tupleDivide((1, 2), (2, 3))─┐
│ (0.5,0.6666666666666666) │
└─────────────────────────────┘
```
## tupleNegate {#tuplenegate}
Calculates the negation of the tuple values.
**Syntax**
```sql
tupleNegate(tuple)
```
**Arguments**
- `tuple` — [Tuple](../../sql-reference/data-types/tuple.md).
**Returned value**
- Tuple with the result of negation.
Type: [Tuple](../../sql-reference/data-types/tuple.md).
**Example**
Query:
```sql
SELECT tupleNegate((1, 2));
```
Result:
```text
┌─tupleNegate((1, 2))─┐
│ (-1,-2) │
└─────────────────────┘
```
## tupleMultiplyByNumber {#tuplemultiplybynumber}
Returns a tuple with all values multiplied by a number.
**Syntax**
```sql
tupleMultiplyByNumber(tuple, number)
```
**Arguments**
- `tuple` — [Tuple](../../sql-reference/data-types/tuple.md).
- `number` — Multiplier. [Int/UInt](../../sql-reference/data-types/int-uint.md), [Float](../../sql-reference/data-types/float.md) or [Decimal](../../sql-reference/data-types/decimal.md).
**Returned value**
- Tuple with multiplied values.
Type: [Tuple](../../sql-reference/data-types/tuple.md).
**Example**
Query:
```sql
SELECT tupleMultiplyByNumber((1, 2), -2.1);
```
Result:
```text
┌─tupleMultiplyByNumber((1, 2), -2.1)─┐
│ (-2.1,-4.2) │
└─────────────────────────────────────┘
```
## tupleDivideByNumber {#tupledividebynumber}
Returns a tuple with all values divided by a number. Note that division by zero will return `inf`.
**Syntax**
```sql
tupleDivideByNumber(tuple, number)
```
**Arguments**
- `tuple` — [Tuple](../../sql-reference/data-types/tuple.md).
- `number` — Divider. [Int/UInt](../../sql-reference/data-types/int-uint.md), [Float](../../sql-reference/data-types/float.md) or [Decimal](../../sql-reference/data-types/decimal.md).
**Returned value**
- Tuple with divided values.
Type: [Tuple](../../sql-reference/data-types/tuple.md).
**Example**
Query:
```sql
SELECT tupleDivideByNumber((1, 2), 0.5);
```
Result:
```text
┌─tupleDivideByNumber((1, 2), 0.5)─┐
│ (2,4) │
└──────────────────────────────────┘
```
## dotProduct {#dotproduct}
Calculates the scalar product of two tuples of the same size.
**Syntax**
```sql
dotProduct(tuple1, tuple2)
```
Alias: `scalarProduct`.
**Arguments**
- `tuple1` — First tuple. [Tuple](../../sql-reference/data-types/tuple.md).
- `tuple2` — Second tuple. [Tuple](../../sql-reference/data-types/tuple.md).
**Returned value**
- Scalar product.
Type: [Int/UInt](../../sql-reference/data-types/int-uint.md), [Float](../../sql-reference/data-types/float.md) or [Decimal](../../sql-reference/data-types/decimal.md).
**Example**
Query:
```sql
SELECT dotProduct((1, 2), (2, 3));
```
Result:
```text
┌─dotProduct((1, 2), (2, 3))─┐
│ 8 │
└────────────────────────────┘
```
## L1Norm {#l1norm}
Calculates the sum of absolute values of a tuple.
**Syntax**
```sql
L1Norm(tuple)
```
Alias: `normL1`.
**Arguments**
- `tuple` — [Tuple](../../sql-reference/data-types/tuple.md).
**Returned value**
- L1-norm or [taxicab geometry](https://en.wikipedia.org/wiki/Taxicab_geometry) distance.
Type: [UInt](../../sql-reference/data-types/int-uint.md), [Float](../../sql-reference/data-types/float.md) or [Decimal](../../sql-reference/data-types/decimal.md).
**Example**
Query:
```sql
SELECT L1Norm((1, 2));
```
Result:
```text
┌─L1Norm((1, 2))─┐
│ 3 │
└────────────────┘
```
## L2Norm {#l2norm}
Calculates the square root of the sum of the squares of the tuple values.
**Syntax**
```sql
L2Norm(tuple)
```
Alias: `normL2`.
**Arguments**
- `tuple` — [Tuple](../../sql-reference/data-types/tuple.md).
**Returned value**
- L2-norm or [Euclidean distance](https://en.wikipedia.org/wiki/Euclidean_distance).
Type: [Float](../../sql-reference/data-types/float.md).
**Example**
Query:
```sql
SELECT L2Norm((1, 2));
```
Result:
```text
┌───L2Norm((1, 2))─┐
│ 2.23606797749979 │
└──────────────────┘
```
## LinfNorm {#linfnorm}
Calculates the maximum of absolute values of a tuple.
**Syntax**
```sql
LinfNorm(tuple)
```
Alias: `normLinf`.
**Arguments**
- `tuple` — [Tuple](../../sql-reference/data-types/tuple.md).
**Returned value**
- Linf-norm or the maximum absolute value.
Type: [Float](../../sql-reference/data-types/float.md).
**Example**
Query:
```sql
SELECT LinfNorm((1, -2));
```
Result:
```text
┌─LinfNorm((1, -2))─┐
│ 2 │
└───────────────────┘
```
## LpNorm {#lpnorm}
Calculates the root of `p`-th power of the sum of the absolute values of a tuple in the power of `p`.
**Syntax**
```sql
LpNorm(tuple, p)
```
Alias: `normLp`.
**Arguments**
- `tuple` — [Tuple](../../sql-reference/data-types/tuple.md).
- `p` — The power. Possible values: real number in `[1; inf)`. [UInt](../../sql-reference/data-types/int-uint.md) or [Float](../../sql-reference/data-types/float.md).
**Returned value**
- [Lp-norm](https://en.wikipedia.org/wiki/Norm_(mathematics)#p-norm)
Type: [Float](../../sql-reference/data-types/float.md).
**Example**
Query:
```sql
SELECT LpNorm((1, -2), 2);
```
Result:
```text
┌─LpNorm((1, -2), 2)─┐
│ 2.23606797749979 │
└────────────────────┘
```
## L1Distance {#l1distance}
Calculates the distance between two points (the values of the tuples are the coordinates) in `L1` space (1-norm ([taxicab geometry](https://en.wikipedia.org/wiki/Taxicab_geometry) distance)).
**Syntax**
```sql
L1Distance(tuple1, tuple2)
```
Alias: `distanceL1`.
**Arguments**
- `tuple1` — First tuple. [Tuple](../../sql-reference/data-types/tuple.md).
- `tuple1` — Second tuple. [Tuple](../../sql-reference/data-types/tuple.md).
**Returned value**
- 1-norm distance.
Type: [Float](../../sql-reference/data-types/float.md).
**Example**
Query:
```sql
SELECT L1Distance((1, 2), (2, 3));
```
Result:
```text
┌─L1Distance((1, 2), (2, 3))─┐
│ 2 │
└────────────────────────────┘
```
## L2Distance {#l2distance}
Calculates the distance between two points (the values of the tuples are the coordinates) in Euclidean space ([Euclidean distance](https://en.wikipedia.org/wiki/Euclidean_distance)).
**Syntax**
```sql
L2Distance(tuple1, tuple2)
```
Alias: `distanceL2`.
**Arguments**
- `tuple1` — First tuple. [Tuple](../../sql-reference/data-types/tuple.md).
- `tuple1` — Second tuple. [Tuple](../../sql-reference/data-types/tuple.md).
**Returned value**
- 2-norm distance.
Type: [Float](../../sql-reference/data-types/float.md).
**Example**
Query:
```sql
SELECT L2Distance((1, 2), (2, 3));
```
Result:
```text
┌─L2Distance((1, 2), (2, 3))─┐
│ 1.4142135623730951 │
└────────────────────────────┘
```
## LinfDistance {#linfdistance}
Calculates the distance between two points (the values of the tuples are the coordinates) in `L_{inf}` space ([maximum norm](https://en.wikipedia.org/wiki/Norm_(mathematics)#Maximum_norm_(special_case_of:_infinity_norm,_uniform_norm,_or_supremum_norm))).
**Syntax**
```sql
LinfDistance(tuple1, tuple2)
```
Alias: `distanceLinf`.
**Arguments**
- `tuple1` — First tuple. [Tuple](../../sql-reference/data-types/tuple.md).
- `tuple1` — Second tuple. [Tuple](../../sql-reference/data-types/tuple.md).
**Returned value**
- Infinity-norm distance.
Type: [Float](../../sql-reference/data-types/float.md).
**Example**
Query:
```sql
SELECT LinfDistance((1, 2), (2, 3));
```
Result:
```text
┌─LinfDistance((1, 2), (2, 3))─┐
│ 1 │
└──────────────────────────────┘
```
## LpDistance {#lpdistance}
Calculates the distance between two points (the values of the tuples are the coordinates) in `Lp` space ([p-norm distance](https://en.wikipedia.org/wiki/Norm_(mathematics)#p-norm)).
**Syntax**
```sql
LpDistance(tuple1, tuple2, p)
```
Alias: `distanceLp`.
**Arguments**
- `tuple1` — First tuple. [Tuple](../../sql-reference/data-types/tuple.md).
- `tuple1` — Second tuple. [Tuple](../../sql-reference/data-types/tuple.md).
- `p` — The power. Possible values: real number from `[1; inf)`. [UInt](../../sql-reference/data-types/int-uint.md) or [Float](../../sql-reference/data-types/float.md).
**Returned value**
- p-norm distance.
Type: [Float](../../sql-reference/data-types/float.md).
**Example**
Query:
```sql
SELECT LpDistance((1, 2), (2, 3), 3);
```
Result:
```text
┌─LpDistance((1, 2), (2, 3), 3)─┐
│ 1.2599210498948732 │
└───────────────────────────────┘
```
## L1Normalize {#l1normalize}
Calculates the unit vector of a given vector (the values of the tuple are the coordinates) in `L1` space ([taxicab geometry](https://en.wikipedia.org/wiki/Taxicab_geometry)).
**Syntax**
```sql
L1Normalize(tuple)
```
Alias: `normalizeL1`.
**Arguments**
- `tuple` — [Tuple](../../sql-reference/data-types/tuple.md).
**Returned value**
- Unit vector.
Type: [Tuple](../../sql-reference/data-types/tuple.md) of [Float](../../sql-reference/data-types/float.md).
**Example**
Query:
```sql
SELECT L1Normalize((1, 2));
```
Result:
```text
┌─L1Normalize((1, 2))─────────────────────┐
│ (0.3333333333333333,0.6666666666666666) │
└─────────────────────────────────────────┘
```
## L2Normalize {#l2normalize}
Calculates the unit vector of a given vector (the values of the tuple are the coordinates) in Euclidean space (using [Euclidean distance](https://en.wikipedia.org/wiki/Euclidean_distance)).
**Syntax**
```sql
L2Normalize(tuple)
```
Alias: `normalizeL1`.
**Arguments**
- `tuple` — [Tuple](../../sql-reference/data-types/tuple.md).
**Returned value**
- Unit vector.
Type: [Tuple](../../sql-reference/data-types/tuple.md) of [Float](../../sql-reference/data-types/float.md).
**Example**
Query:
```sql
SELECT L2Normalize((3, 4));
```
Result:
```text
┌─L2Normalize((3, 4))─┐
│ (0.6,0.8) │
└─────────────────────┘
```
## LinfNormalize {#linfnormalize}
Calculates the unit vector of a given vector (the values of the tuple are the coordinates) in `L_{inf}` space (using [maximum norm](https://en.wikipedia.org/wiki/Norm_(mathematics)#Maximum_norm_(special_case_of:_infinity_norm,_uniform_norm,_or_supremum_norm))).
**Syntax**
```sql
LinfNormalize(tuple)
```
Alias: `normalizeLinf `.
**Arguments**
- `tuple` — [Tuple](../../sql-reference/data-types/tuple.md).
**Returned value**
- Unit vector.
Type: [Tuple](../../sql-reference/data-types/tuple.md) of [Float](../../sql-reference/data-types/float.md).
**Example**
Query:
```sql
SELECT LinfNormalize((3, 4));
```
Result:
```text
┌─LinfNormalize((3, 4))─┐
│ (0.75,1) │
└───────────────────────┘
```
## LpNormalize {#lpnormalize}
Calculates the unit vector of a given vector (the values of the tuple are the coordinates) in `Lp` space (using [p-norm](https://en.wikipedia.org/wiki/Norm_(mathematics)#p-norm)).
**Syntax**
```sql
LpNormalize(tuple, p)
```
Alias: `normalizeLp `.
**Arguments**
- `tuple` — [Tuple](../../sql-reference/data-types/tuple.md).
- `p` — The power. Possible values: any number from [1;inf). [UInt](../../sql-reference/data-types/int-uint.md) or [Float](../../sql-reference/data-types/float.md).
**Returned value**
- Unit vector.
Type: [Tuple](../../sql-reference/data-types/tuple.md) of [Float](../../sql-reference/data-types/float.md).
**Example**
Query:
```sql
SELECT LpNormalize((3, 4),5);
```
Result:
```text
┌─LpNormalize((3, 4), 5)──────────────────┐
│ (0.7187302630182624,0.9583070173576831) │
└─────────────────────────────────────────┘
```
## cosineDistance {#cosinedistance}
Calculates the cosine distance between two vectors (the values of the tuples are the coordinates). The less the returned value is, the more similar are the vectors.
**Syntax**
```sql
cosineDistance(tuple1, tuple2)
```
**Arguments**
- `tuple1` — First tuple. [Tuple](../../sql-reference/data-types/tuple.md).
- `tuple2` — Second tuple. [Tuple](../../sql-reference/data-types/tuple.md).
**Returned value**
- Cosine of the angle between two vectors substracted from one.
Type: [Float](../../sql-reference/data-types/float.md).
**Example**
Query:
```sql
SELECT cosineDistance((1, 2), (2, 3));
```
Result:
```text
┌─cosineDistance((1, 2), (2, 3))─┐
│ 0.007722123286332261 │
└────────────────────────────────┘
```

View File

@ -17,20 +17,30 @@ ClickHouse transforms operators to their corresponding functions at the query pa
`-a` The `negate (a)` function.
For tuple negation: [tupleNegate](../../sql-reference/functions/tuple-functions.md#tuplenegate).
## Multiplication and Division Operators {#multiplication-and-division-operators}
`a * b` The `multiply (a, b)` function.
For multiplying tuple by number: [tupleMultiplyByNumber](../../sql-reference/functions/tuple-functions.md#tuplemultiplybynumber), for scalar profuct: [dotProduct](../../sql-reference/functions/tuple-functions.md#dotproduct).
`a / b` The `divide(a, b)` function.
For dividing tuple by number: [tupleDivideByNumber](../../sql-reference/functions/tuple-functions.md#tupledividebynumber).
`a % b` The `modulo(a, b)` function.
## Addition and Subtraction Operators {#addition-and-subtraction-operators}
`a + b` The `plus(a, b)` function.
For tuple addiction: [tuplePlus](../../sql-reference/functions/tuple-functions.md#tupleplus).
`a - b` The `minus(a, b)` function.
For tuple subtraction: [tupleMinus](../../sql-reference/functions/tuple-functions.md#tupleminus).
## Comparison Operators {#comparison-operators}
`a = b` The `equals(a, b)` function.
@ -71,6 +81,53 @@ ClickHouse transforms operators to their corresponding functions at the query pa
`a GLOBAL NOT IN ...` The `globalNotIn(a, b)` function.
`a = ANY (subquery)` The `in(a, subquery)` function.
`a != ANY (subquery)` The same as `a NOT IN (SELECT singleValueOrNull(*) FROM subquery)`.
`a = ALL (subquery)` The same as `a IN (SELECT singleValueOrNull(*) FROM subquery)`.
`a != ALL (subquery)` The `notIn(a, subquery)` function.
**Examples**
Query with ALL:
``` sql
SELECT number AS a FROM numbers(10) WHERE a > ALL (SELECT number FROM numbers(3, 3));
```
Result:
``` text
┌─a─┐
│ 6 │
│ 7 │
│ 8 │
│ 9 │
└───┘
```
Query with ANY:
``` sql
SELECT number AS a FROM numbers(10) WHERE a > ANY (SELECT number FROM numbers(3, 3));
```
Result:
``` text
┌─a─┐
│ 4 │
│ 5 │
│ 6 │
│ 7 │
│ 8 │
│ 9 │
└───┘
```
## Operators for Working with Dates and Times {#operators-datetime}
### EXTRACT {#operator-extract}

View File

@ -119,3 +119,14 @@ Performance will not decrease if:
- Data is added in real time.
- You upload data that is usually sorted by time.
It's also possible to asynchronously insert data in small but frequent inserts. The data from such insertions is combined into batches and then safely inserted into a table. To enable the asynchronous mode, switch on the [async_insert](../../operations/settings/settings.md#async-insert) setting. Note that asynchronous insertions are supported only over HTTP protocol, and deduplication is not supported for them.
**See Also**
- [async_insert](../../operations/settings/settings.md#async-insert)
- [async_insert_threads](../../operations/settings/settings.md#async-insert-threads)
- [wait_for_async_insert](../../operations/settings/settings.md#wait-for-async-insert)
- [wait_for_async_insert_timeout](../../operations/settings/settings.md#wait-for-async-insert-timeout)
- [async_insert_max_data_size](../../operations/settings/settings.md#async-insert-max-data-size)
- [async_insert_busy_timeout_ms](../../operations/settings/settings.md#async-insert-busy-timeout-ms)
- [async_insert_stale_timeout_ms](../../operations/settings/settings.md#async-insert-stale-timeout-ms)

View File

@ -0,0 +1,69 @@
---
toc_title: EXCEPT
---
# EXCEPT Clause {#except-clause}
The `EXCEPT` clause returns only those rows that result from the first query without the second. The queries must match the number of columns, order, and type. The result of `EXCEPT` can contain duplicate rows.
Multiple `EXCEPT` statements are executed left to right if parenthesis are not specified. The `EXCEPT` operator has the same priority as the `UNION` clause and lower priority than the `INTERSECT` clause.
``` sql
SELECT column1 [, column2 ]
FROM table1
[WHERE condition]
EXCEPT
SELECT column1 [, column2 ]
FROM table2
[WHERE condition]
```
The condition could be any expression based on your requirements.
**Examples**
Query:
``` sql
SELECT number FROM numbers(1,10) EXCEPT SELECT number FROM numbers(3,6);
```
Result:
``` text
┌─number─┐
│ 1 │
│ 2 │
│ 9 │
│ 10 │
└────────┘
```
Query:
``` sql
CREATE TABLE t1(one String, two String, three String) ENGINE=Memory();
CREATE TABLE t2(four String, five String, six String) ENGINE=Memory();
INSERT INTO t1 VALUES ('q', 'm', 'b'), ('s', 'd', 'f'), ('l', 'p', 'o'), ('s', 'd', 'f'), ('s', 'd', 'f'), ('k', 't', 'd'), ('l', 'p', 'o');
INSERT INTO t2 VALUES ('q', 'm', 'b'), ('b', 'd', 'k'), ('s', 'y', 't'), ('s', 'd', 'f'), ('m', 'f', 'o'), ('k', 'k', 'd');
SELECT * FROM t1 EXCEPT SELECT * FROM t2;
```
Result:
``` text
┌─one─┬─two─┬─three─┐
│ l │ p │ o │
│ k │ t │ d │
│ l │ p │ o │
└─────┴─────┴───────┘
```
**See Also**
- [UNION](union.md#union-clause)
- [INTERSECT](intersect.md#intersect-clause)

View File

@ -49,6 +49,8 @@ Specifics of each optional clause are covered in separate sections, which are li
- [LIMIT clause](../../../sql-reference/statements/select/limit.md)
- [OFFSET clause](../../../sql-reference/statements/select/offset.md)
- [UNION clause](../../../sql-reference/statements/select/union.md)
- [INTERSECT clause](../../../sql-reference/statements/select/intersect.md)
- [EXCEPT clause](../../../sql-reference/statements/select/except.md)
- [INTO OUTFILE clause](../../../sql-reference/statements/select/into-outfile.md)
- [FORMAT clause](../../../sql-reference/statements/select/format.md)

View File

@ -0,0 +1,73 @@
---
toc_title: INTERSECT
---
# INTERSECT Clause {#intersect-clause}
The `INTERSECT` clause returns only those rows that result from both the first and the second queries. The queries must match the number of columns, order, and type. The result of `INTERSECT` can contain duplicate rows.
Multiple `INTERSECT` statements are executes left to right if parenthesis are not specified. The `INTERSECT` operator has a higher priority than the `UNION` and `EXCEPT` clause.
``` sql
SELECT column1 [, column2 ]
FROM table1
[WHERE condition]
INTERSECT
SELECT column1 [, column2 ]
FROM table2
[WHERE condition]
```
The condition could be any expression based on your requirements.
**Examples**
Query:
``` sql
SELECT number FROM numbers(1,10) INTERSECT SELECT number FROM numbers(3,6);
```
Result:
``` text
┌─number─┐
│ 3 │
│ 4 │
│ 5 │
│ 6 │
│ 7 │
│ 8 │
└────────┘
```
Query:
``` sql
CREATE TABLE t1(one String, two String, three String) ENGINE=Memory();
CREATE TABLE t2(four String, five String, six String) ENGINE=Memory();
INSERT INTO t1 VALUES ('q', 'm', 'b'), ('s', 'd', 'f'), ('l', 'p', 'o'), ('s', 'd', 'f'), ('s', 'd', 'f'), ('k', 't', 'd'), ('l', 'p', 'o');
INSERT INTO t2 VALUES ('q', 'm', 'b'), ('b', 'd', 'k'), ('s', 'y', 't'), ('s', 'd', 'f'), ('m', 'f', 'o'), ('k', 'k', 'd');
SELECT * FROM t1 INTERSECT SELECT * FROM t2;
```
Result:
``` text
┌─one─┬─two─┬─three─┐
│ q │ m │ b │
│ s │ d │ f │
│ s │ d │ f │
│ s │ d │ f │
└─────┴─────┴───────┘
```
**See Also**
- [UNION](union.md#union-clause)
- [EXCEPT](except.md#except-clause)

View File

@ -78,7 +78,7 @@ HDDの場合、ライトキャッシュを有効にします。
## ファイルシス {#file-system}
Ext4は最も信頼性の高いオプションです。 マウントオプションの設定 `noatime, nobarrier`.
Ext4は最も信頼性の高いオプションです。 マウントオプションの設定 `noatime`.
XFSも適していますが、ClickHouseで徹底的にテストされていません。
他のほとんどのファイルシステム仕様。 ファイルシステムの遅配ます。

View File

@ -15,7 +15,7 @@ CREATE TABLE [IF NOT EXISTS] [db.]table_name
name1 [type1],
name2 [type2],
...
) ENGINE = MongoDB(host:port, database, collection, user, password);
) ENGINE = MongoDB(host:port, database, collection, user, password [, options]);
```
**Параметры движка**
@ -30,11 +30,13 @@ CREATE TABLE [IF NOT EXISTS] [db.]table_name
- `password` — пароль пользователя.
- `options` — MongoDB connection string options (optional parameter).
## Примеры использования {#usage-example}
Таблица в ClickHouse для чтения данных из колекции MongoDB:
Создание таблицы в ClickHouse для чтения данных из коллекции MongoDB:
``` text
``` sql
CREATE TABLE mongo_table
(
key UInt64,
@ -42,6 +44,18 @@ CREATE TABLE mongo_table
) ENGINE = MongoDB('mongo1:27017', 'test', 'simple_table', 'testuser', 'clickhouse');
```
Чтение с сервера MongoDB, защищенного SSL:
``` sql
CREATE TABLE mongo_table_ssl
(
key UInt64,
data String
) ENGINE = MongoDB('mongo2:27017', 'test', 'simple_table', 'testuser', 'clickhouse', 'ssl=true');
```
Запрос к таблице:
``` sql

View File

@ -29,7 +29,7 @@ grep -q sse4_2 /proc/cpuinfo && echo "SSE 4.2 supported" || echo "SSE 4.2 not su
Также эти пакеты можно скачать и установить вручную отсюда: https://repo.clickhouse.com/deb/stable/main/.
Если вы хотите использовать наиболее свежую версию, замените `stable` на `testing` (рекомендуется для тестовых окружений).
Чтобы использовать различные [версии ClickHouse](../faq/operations/production.md) в зависимости от ваших потребностей, вы можете заменить `stable` на `lts` или `testing`.
Также вы можете вручную скачать и установить пакеты из [репозитория](https://repo.clickhouse.com/deb/stable/main/).

View File

@ -611,7 +611,7 @@ ClickHouse проверяет условия для `min_part_size` и `min_part
## max_concurrent_queries {#max-concurrent-queries}
Определяет максимальное количество одновременно обрабатываемых запросов, связанных с таблицей семейства `MergeTree`. Запросы также могут быть ограничены настройками: [max_concurrent_queries_for_all_users](#max-concurrent-queries-for-all-users), [min_marks_to_honor_max_concurrent_queries](#min-marks-to-honor-max-concurrent-queries).
Определяет максимальное количество одновременно обрабатываемых запросов, связанных с таблицей семейства `MergeTree`. Запросы также могут быть ограничены настройками: [max_concurrent_queries_for_user](#max-concurrent-queries-for-user), [max_concurrent_queries_for_all_users](#max-concurrent-queries-for-all-users), [min_marks_to_honor_max_concurrent_queries](#min-marks-to-honor-max-concurrent-queries).
!!! info "Примечание"
Параметры этих настроек могут быть изменены во время выполнения запросов и вступят в силу немедленно. Запросы, которые уже запущены, выполнятся без изменений.
@ -627,6 +627,21 @@ ClickHouse проверяет условия для `min_part_size` и `min_part
<max_concurrent_queries>100</max_concurrent_queries>
```
## max_concurrent_queries_for_user {#max-concurrent-queries-for-user}
Определяет максимальное количество одновременно обрабатываемых запросов, связанных с таблицей семейства `MergeTree`, для пользователя.
Возможные значения:
- Положительное целое число.
- 0 — выключена.
**Пример**
``` xml
<max_concurrent_queries_for_user>5</max_concurrent_queries_for_user>
```
## max_concurrent_queries_for_all_users {#max-concurrent-queries-for-all-users}
Если значение этой настройки меньше или равно текущему количеству одновременно обрабатываемых запросов, то будет сгенерировано исключение.

View File

@ -28,7 +28,7 @@ toc_title: "Настройки пользователей"
<profile>profile_name</profile>
<quota>default</quota>
<default_database>default<default_database>
<databases>
<database_name>
<table_name>

View File

@ -3640,3 +3640,87 @@ SELECT * FROM positional_arguments ORDER BY 2,3;
**См. также**
- настройка [optimize_move_to_prewhere](#optimize_move_to_prewhere)
## async_insert {#async-insert}
Включает или отключает асинхронные вставки. Работает только для вставок по протоколу HTTP. Обратите внимание, что при таких вставках дедупликация не производится.
Если включено, данные собираются в пачки перед вставкой в таблицу. Это позволяет производить мелкие и частые вставки в ClickHouse (до 15000 запросов в секунду) без промежуточных таблиц.
Вставка данных происходит либо как только объем вставляемых данных превышает [async_insert_max_data_size](#async-insert-max-data-size), либо через [async_insert_busy_timeout_ms](#async-insert-busy-timeout-ms) миллисекунд после первого запроса `INSERT`. Если в [async_insert_stale_timeout_ms](#async-insert-stale-timeout-ms) задано ненулевое значение, то данные вставляются через `async_insert_stale_timeout_ms` миллисекунд после последнего запроса.
Если включен параметр [wait_for_async_insert](#wait-for-async-insert), каждый клиент ждет, пока данные будут сброшены в таблицу. Иначе запрос будет обработан почти моментально, даже если данные еще не вставлены.
Возможные значения:
- 0 — вставки производятся синхронно, один запрос за другим.
- 1 — включены множественные асинхронные вставки.
Значение по умолчанию: `0`.
## async_insert_threads {#async-insert-threads}
Максимальное число потоков для фоновой обработки и вставки данных.
Возможные значения:
- Положительное целое число.
- 0 — асинхронные вставки отключены.
Значение по умолчанию: `16`.
## wait_for_async_insert {#wait-for-async-insert}
Включает или отключает ожидание обработки асинхронных вставок. Если включено, клиент выведет `OK` только после того, как данные вставлены. Иначе будет выведен `OK`, даже если вставка не произошла.
Возможные значения:
- 0 — сервер возвращает `OK` даже если вставка данных еще не завершена.
- 1 — сервер возвращает `OK` только после завершения вставки данных.
Значение по умолчанию: `1`.
## wait_for_async_insert_timeout {#wait-for-async-insert-timeout}
Время ожидания в секундах, выделяемое для обработки асинхронной вставки.
Возможные значения:
- Положительное целое число.
- 0 — ожидание отключено.
Значение по умолчанию: [lock_acquire_timeout](#lock_acquire_timeout).
## async_insert_max_data_size {#async-insert-max-data-size}
Максимальный размер необработанных данных (в байтах), собранных за запрос, перед их вставкой.
Возможные значения:
- Положительное целое число.
- 0 — асинхронные вставки отключены.
Значение по умолчанию: `1000000`.
## async_insert_busy_timeout_ms {#async-insert-busy-timeout-ms}
Максимальное время ожидания в миллисекундах после первого запроса `INSERT` и перед вставкой данных.
Возможные значения:
- Положительное целое число.
- 0 — ожидание отключено.
Значение по умолчанию: `200`.
## async_insert_stale_timeout_ms {#async-insert-stale-timeout-ms}
Максимальное время ожидания в миллисекундах после последнего запроса `INSERT` и перед вставкой данных. Если установлено ненулевое значение, [async_insert_busy_timeout_ms](#async-insert-busy-timeout-ms) будет продлеваться с каждым запросом `INSERT`, пока не будет превышен [async_insert_max_data_size](#async-insert-max-data-size).
Возможные значения:
- Положительное целое число.
- 0 — ожидание отключено.
Значение по умолчанию: `0`.

View File

@ -6,20 +6,12 @@ toc_priority: 106
Вычисляет значение `arg` при максимальном значении `val`. Если есть несколько разных значений `arg` для максимальных значений `val`, возвращает первое попавшееся из таких значений.
Если функции передан кортеж, то будет выведен кортеж с максимальным значением `val`. Удобно использовать для работы с [SimpleAggregateFunction](../../../sql-reference/data-types/simpleaggregatefunction.md).
**Синтаксис**
``` sql
argMax(arg, val)
```
или
``` sql
argMax(tuple(arg, val))
```
**Аргументы**
- `arg` — аргумент.
@ -31,12 +23,6 @@ argMax(tuple(arg, val))
Тип: соответствует типу `arg`.
Если передан кортеж:
- кортеж `(arg, val)` c максимальным значением `val` и соответствующим ему `arg`.
Тип: [Tuple](../../../sql-reference/data-types/tuple.md).
**Пример**
Исходная таблица:
@ -52,14 +38,14 @@ argMax(tuple(arg, val))
Запрос:
``` sql
SELECT argMax(user, salary), argMax(tuple(user, salary), salary), argMax(tuple(user, salary)) FROM salary;
SELECT argMax(user, salary), argMax(tuple(user, salary), salary) FROM salary;
```
Результат:
``` text
┌─argMax(user, salary)─┬─argMax(tuple(user, salary), salary)─┬─argMax(tuple(user, salary))─
│ director │ ('director',5000) │ ('director',5000) │
└──────────────────────┴─────────────────────────────────────┴─────────────────────────────
┌─argMax(user, salary)─┬─argMax(tuple(user, salary), salary)─┐
│ director │ ('director',5000) │
└──────────────────────┴─────────────────────────────────────┘
```

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@ -6,20 +6,12 @@ toc_priority: 105
Вычисляет значение `arg` при минимальном значении `val`. Если есть несколько разных значений `arg` для минимальных значений `val`, возвращает первое попавшееся из таких значений.
Если функции передан кортеж, то будет выведен кортеж с минимальным значением `val`. Удобно использовать для работы с [SimpleAggregateFunction](../../../sql-reference/data-types/simpleaggregatefunction.md).
**Синтаксис**
``` sql
argMin(arg, val)
```
или
``` sql
argMin(tuple(arg, val))
```
**Аргументы**
- `arg` — аргумент.
@ -31,12 +23,6 @@ argMin(tuple(arg, val))
Тип: соответствует типу `arg`.
Если передан кортеж:
- Кортеж `(arg, val)` c минимальным значением `val` и соответствующим ему `arg`.
Тип: [Tuple](../../../sql-reference/data-types/tuple.md).
**Пример**
Исходная таблица:
@ -52,14 +38,14 @@ argMin(tuple(arg, val))
Запрос:
``` sql
SELECT argMin(user, salary), argMin(tuple(user, salary)) FROM salary;
SELECT argMin(user, salary) FROM salary;
```
Результат:
``` text
┌─argMin(user, salary)─┬─argMin(tuple(user, salary))─
│ worker │ ('worker',1000) │
└──────────────────────┴─────────────────────────────
┌─argMin(user, salary)─┐
│ worker │
└──────────────────────┘
```

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@ -0,0 +1,43 @@
---
toc_priority: 302
---
# entropy {#entropy}
Вычисляет [информационную энтропию](https://ru.wikipedia.org/wiki/%D0%98%D0%BD%D1%84%D0%BE%D1%80%D0%BC%D0%B0%D1%86%D0%B8%D0%BE%D0%BD%D0%BD%D0%B0%D1%8F_%D1%8D%D0%BD%D1%82%D1%80%D0%BE%D0%BF%D0%B8%D1%8F) столбца данных.
**Синтаксис**
``` sql
entropy(val)
```
**Аргументы**
- `val` — столбец значений любого типа
**Возвращаемое значение**
- Информационная энтропия.
Тип: [Float64](../../../sql-reference/data-types/float.md).
**Пример**
Запрос:
``` sql
CREATE TABLE entropy (`vals` UInt32,`strings` String) ENGINE = Memory;
INSERT INTO entropy VALUES (1, 'A'), (1, 'A'), (1,'A'), (1,'A'), (2,'B'), (2,'B'), (2,'C'), (2,'D');
SELECT entropy(vals), entropy(strings) FROM entropy;
```
Результат:
``` text
┌─entropy(vals)─┬─entropy(strings)─┐
│ 1 │ 1.75 │
└───────────────┴──────────────────┘
```

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@ -53,14 +53,17 @@ LAYOUT(LAYOUT_TYPE(param value)) -- layout settings
- [flat](#flat)
- [hashed](#dicts-external_dicts_dict_layout-hashed)
- [sparse_hashed](#dicts-external_dicts_dict_layout-sparse_hashed)
- [cache](#cache)
- [ssd_cache](#ssd-cache)
- [ssd_complex_key_cache](#complex-key-ssd-cache)
- [direct](#direct)
- [range_hashed](#range-hashed)
- [complex_key_hashed](#complex-key-hashed)
- [complex_key_sparse_hashed](#complex-key-sparse-hashed)
- [hashed_array](#dicts-external_dicts_dict_layout-hashed-array)
- [complex_key_hashed_array](#complex-key-hashed-array)
- [range_hashed](#range-hashed)
- [complex_key_range_hashed](#complex-key-range-hashed)
- [cache](#cache)
- [complex_key_cache](#complex-key-cache)
- [ssd_cache](#ssd-cache)
- [complex_key_ssd_cache](#complex-key-ssd-cache)
- [direct](#direct)
- [complex_key_direct](#complex-key-direct)
- [ip_trie](#ip-trie)
@ -140,7 +143,7 @@ LAYOUT(SPARSE_HASHED([PREALLOCATE 0]))
### complex_key_hashed {#complex-key-hashed}
Тип размещения предназначен для использования с составными [ключами](external-dicts-dict-structure.md). Аналогичен `hashed`.
Тип размещения предназначен для использования с составными [ключами](../../../sql-reference/dictionaries/external-dictionaries/external-dicts-dict-structure.md). Аналогичен `hashed`.
Пример конфигурации:
@ -156,6 +159,63 @@ LAYOUT(SPARSE_HASHED([PREALLOCATE 0]))
LAYOUT(COMPLEX_KEY_HASHED())
```
### complex_key_sparse_hashed {#complex-key-sparse-hashed}
Тип размещения предназначен для использования с составными [ключами](../../../sql-reference/dictionaries/external-dictionaries/external-dicts-dict-structure.md). Аналогичен [sparse_hashed](#dicts-external_dicts_dict_layout-sparse_hashed).
Пример конфигурации:
``` xml
<layout>
<complex_key_sparse_hashed />
</layout>
```
или
``` sql
LAYOUT(COMPLEX_KEY_SPARSE_HASHED())
```
### hashed_array {#dicts-external_dicts_dict_layout-hashed-array}
Словарь полностью хранится в оперативной памяти. Каждый атрибут хранится в массиве. Ключевой атрибут хранится в виде хеш-таблицы, где его значение является индексом в массиве атрибутов. Словарь может содержать произвольное количество элементов с произвольными идентификаторами. На практике количество ключей может достигать десятков миллионов элементов.
Поддерживаются все виды источников. При обновлении данные (из файла, из таблицы) считываются целиком.
Пример конфигурации:
``` xml
<layout>
<hashed_array>
</hashed_array>
</layout>
```
или
``` sql
LAYOUT(HASHED_ARRAY())
```
### complex_key_hashed_array {#complex-key-hashed-array}
Тип размещения предназначен для использования с составными [ключами](../../../sql-reference/dictionaries/external-dictionaries/external-dicts-dict-structure.md). Аналогичен [hashed_array](#dicts-external_dicts_dict_layout-hashed-array).
Пример конфигурации:
``` xml
<layout>
<complex_key_hashed_array />
</layout>
```
или
``` sql
LAYOUT(COMPLEX_KEY_HASHED_ARRAY())
```
### range_hashed {#range-hashed}
Словарь хранится в оперативной памяти в виде хэш-таблицы с упорядоченным массивом диапазонов и соответствующих им значений.
@ -297,9 +357,13 @@ RANGE(MIN StartDate MAX EndDate);
При поиске в словаре сначала просматривается кэш. На каждый блок данных, все не найденные в кэше или устаревшие ключи запрашиваются у источника с помощью `SELECT attrs... FROM db.table WHERE id IN (k1, k2, ...)`. Затем, полученные данные записываются в кэш.
Для cache-словарей может быть задано время устаревания [lifetime](external-dicts-dict-lifetime.md) данных в кэше. Если от загрузки данных в ячейке прошло больше времени, чем `lifetime`, то значение не используется, и будет запрошено заново при следующей необходимости его использовать.
Если ключи не были найдены в словаре, то для обновления кэша создается задание и добавляется в очередь обновлений. Параметры очереди обновлений можно устанавливать настройками `max_update_queue_size`, `update_queue_push_timeout_milliseconds`, `query_wait_timeout_milliseconds`, `max_threads_for_updates`
Это наименее эффективный из всех способов размещения словарей. Скорость работы кэша очень сильно зависит от правильности настройки и сценария использования. Словарь типа cache показывает высокую производительность лишь при достаточно больших hit rate-ах (рекомендуется 99% и выше). Посмотреть средний hit rate можно в таблице `system.dictionaries`.
Для cache-словарей при помощи настройки `allow_read_expired_keys` может быть задано время устаревания [lifetime](../../../sql-reference/dictionaries/external-dictionaries/external-dicts-dict-lifetime.md) данных в кэше. Если с момента загрузки данных в ячейку прошло больше времени, чем `lifetime`, то значение не используется, а ключ устаревает. Ключ будет запрошен заново при следующей необходимости его использовать.
Это наименее эффективный из всех способов размещения словарей. Скорость работы кэша очень сильно зависит от правильности настройки и сценария использования. Словарь типа `cache` показывает высокую производительность лишь при достаточно большой частоте успешных обращений (рекомендуется 99% и выше). Посмотреть среднюю частоту успешных обращений (`hit rate`) можно в таблице [system.dictionaries](../../../operations/system-tables/dictionaries.md).
Если параметр `allow_read_expired_keys` выставлен в 1 (0 по умолчанию), то словарь поддерживает асинхронные обновления. Если клиент запрашивает ключи, которые находятся в кэше, но при этом некоторые из них устарели, то словарь вернет устаревшие ключи клиенту и запросит их асинхронно у источника.
Чтобы увеличить производительность кэша, используйте подзапрос с `LIMIT`, а снаружи вызывайте функцию со словарём.
@ -312,6 +376,16 @@ RANGE(MIN StartDate MAX EndDate);
<cache>
<!-- Размер кэша в количестве ячеек. Округляется вверх до степени двух. -->
<size_in_cells>1000000000</size_in_cells>
<!-- Позволить читать устаревшие ключи. -->
<allow_read_expired_keys>0</allow_read_expired_keys>
<!-- Максимальный размер очереди обновлений. -->
<max_update_queue_size>100000</max_update_queue_size>
<!-- Максимальное время (в миллисекундах) для отправки в очередь. -->
<update_queue_push_timeout_milliseconds>10</update_queue_push_timeout_milliseconds>
<!-- Максимальное время ожидания (в миллисекундах) для выполнения обновлений. -->
<query_wait_timeout_milliseconds>60000</query_wait_timeout_milliseconds>
<!-- Максимальное число потоков для обновления кэша словаря. -->
<max_threads_for_updates>4</max_threads_for_updates>
</cache>
</layout>
```
@ -338,7 +412,7 @@ LAYOUT(CACHE(SIZE_IN_CELLS 1000000000))
### ssd_cache {#ssd-cache}
Похож на `cache`, но хранит данные на SSD и индекс в оперативной памяти.
Похож на `cache`, но хранит данные на SSD, а индекс в оперативной памяти. Все параметры, относящиеся к очереди обновлений, могут также быть применены к SSD-кэш словарям.
``` xml
<layout>

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@ -83,3 +83,78 @@ SELECT toTypeName(0), toTypeName(0 + 0), toTypeName(0 + 0 + 0), toTypeName(0 + 0
Вычисляет наименьшее общее кратное чисел.
При делении на ноль или при делении минимального отрицательного числа на минус единицу, кидается исключение.
## max2 {#max2}
Сравнивает два числа и возвращает максимум. Возвращаемое значение приводится к типу [Float64](../../sql-reference/data-types/float.md).
**Синтаксис**
```sql
max2(value1, value2)
```
**Аргументы**
- `value1` — первое число. [Int/UInt](../../sql-reference/data-types/int-uint.md) или [Float](../../sql-reference/data-types/float.md).
- `value2` — второе число. [Int/UInt](../../sql-reference/data-types/int-uint.md) или [Float](../../sql-reference/data-types/float.md).
**Возвращаемое значение**
- Максимальное значение среди двух чисел.
Тип: [Float](../../sql-reference/data-types/float.md).
**Пример**
Запрос:
```sql
SELECT max2(-1, 2);
```
Результат:
```text
┌─max2(-1, 2)─┐
│ 2 │
└─────────────┘
```
## min2 {#min2}
Сравнивает два числа и возвращает минимум. Возвращаемое значение приводится к типу [Float64](../../sql-reference/data-types/float.md).
**Синтаксис**
```sql
min2(value1, value2)
```
**Аргументы**
- `value1` — первое число. [Int/UInt](../../sql-reference/data-types/int-uint.md) или [Float](../../sql-reference/data-types/float.md).
- `value2` — второе число. [Int/UInt](../../sql-reference/data-types/int-uint.md) или [Float](../../sql-reference/data-types/float.md).
**Возвращаемое значение**
- Минимальное значение среди двух чисел.
Тип: [Float](../../sql-reference/data-types/float.md).
**Пример**
Запрос:
```sql
SELECT min2(-1, 2);
```
Результат:
```text
┌─min2(-1, 2)─┐
│ -1 │
└─────────────┘
```

View File

@ -307,6 +307,76 @@ SELECT JSONExtractKeysAndValuesRaw('{"a": [-100, 200.0], "b":{"c": {"d": "hello"
└───────────────────────────────────────────────────────────────────────────────────────────────────────┘
```
## JSON_EXISTS(json, path) {#json-exists}
Если значение существует в документе JSON, то возвращается 1.
Если значение не существует, то возвращается 0.
Пример:
``` sql
SELECT JSON_EXISTS('{"hello":1}', '$.hello');
SELECT JSON_EXISTS('{"hello":{"world":1}}', '$.hello.world');
SELECT JSON_EXISTS('{"hello":["world"]}', '$.hello[*]');
SELECT JSON_EXISTS('{"hello":["world"]}', '$.hello[0]');
```
!!! note "Примечание"
до версии 21.11 порядок аргументов функции был обратный, т.е. JSON_EXISTS(path, json)
## JSON_QUERY(json, path) {#json-query}
Парсит JSON и извлекает значение как JSON массив или JSON объект.
Если значение не существует, то возвращается пустая строка.
Пример:
``` sql
SELECT JSON_QUERY('{"hello":"world"}', '$.hello');
SELECT JSON_QUERY('{"array":[[0, 1, 2, 3, 4, 5], [0, -1, -2, -3, -4, -5]]}', '$.array[*][0 to 2, 4]');
SELECT JSON_QUERY('{"hello":2}', '$.hello');
SELECT toTypeName(JSON_QUERY('{"hello":2}', '$.hello'));
```
Результат:
``` text
["world"]
[0, 1, 4, 0, -1, -4]
[2]
String
```
!!! note "Примечание"
до версии 21.11 порядок аргументов функции был обратный, т.е. JSON_QUERY(path, json)
## JSON_VALUE(json, path) {#json-value}
Парсит JSON и извлекает значение как JSON скаляр.
Если значение не существует, то возвращается пустая строка.
Пример:
``` sql
SELECT JSON_VALUE('{"hello":"world"}', '$.hello');
SELECT JSON_VALUE('{"array":[[0, 1, 2, 3, 4, 5], [0, -1, -2, -3, -4, -5]]}', '$.array[*][0 to 2, 4]');
SELECT JSON_VALUE('{"hello":2}', '$.hello');
SELECT toTypeName(JSON_VALUE('{"hello":2}', '$.hello'));
```
Результат:
``` text
"world"
0
2
String
```
!!! note "Примечание"
до версии 21.11 порядок аргументов функции был обратный, т.е. JSON_VALUE(path, json)
## toJSONString {#tojsonstring}

View File

@ -2375,3 +2375,39 @@ shardCount()
**См. также**
- Пример использования функции [shardNum()](#shard-num) также содержит вызов `shardCount()`.
## getOSKernelVersion {#getoskernelversion}
Возвращает строку с текущей версией ядра ОС.
**Синтаксис**
``` sql
getOSKernelVersion()
```
**Аргументы**
- Нет.
**Возвращаемое значение**
- Текущая версия ядра ОС.
Тип: [String](../../sql-reference/data-types/string.md).
**Пример**
Запрос:
``` sql
SELECT getOSKernelVersion();
```
Результат:
``` text
┌─getOSKernelVersion()────┐
│ Linux 4.15.0-55-generic │
└─────────────────────────┘
```

View File

@ -232,3 +232,41 @@ SELECT alphaTokens('abca1abc');
│ ['abca','abc'] │
└─────────────────────────┘
```
## ngrams {#ngrams}
Выделяет из UTF-8 строки отрезки (n-граммы) размером `ngramsize` символов.
**Синтаксис**
``` sql
ngrams(string, ngramsize)
```
**Аргументы**
- `string` — строка. [String](../../sql-reference/data-types/string.md) or [FixedString](../../sql-reference/data-types/fixedstring.md).
- `ngramsize` — размер n-грамм. [UInt](../../sql-reference/data-types/int-uint.md).
**Возвращаемые значения**
- Массив с n-граммами.
Тип: [Array](../../sql-reference/data-types/array.md)([FixedString](../../sql-reference/data-types/fixedstring.md)).
**Пример**
Запрос:
``` sql
SELECT ngrams('ClickHouse', 3);
```
Результат:
``` text
┌─ngrams('ClickHouse', 3)───────────────────────────┐
│ ['Cli','lic','ick','ckH','kHo','Hou','ous','use'] │
└───────────────────────────────────────────────────┘
```

View File

@ -163,3 +163,805 @@ SELECT tupleHammingDistance(wordShingleMinHash(string), wordShingleMinHashCaseIn
│ 2 │
└─────────────────┘
```
## tuplePlus {#tupleplus}
Вычисляет сумму соответствующих значений двух кортежей одинакового размера.
**Синтаксис**
```sql
tuplePlus(tuple1, tuple2)
```
Синоним: `vectorSum`.
**Аргументы**
- `tuple1` — первый кортеж. [Tuple](../../sql-reference/data-types/tuple.md).
- `tuple2` — второй кортеж. [Tuple](../../sql-reference/data-types/tuple.md).
**Возвращаемое значение**
- Кортеж с суммами.
Тип: [Tuple](../../sql-reference/data-types/tuple.md).
**Пример**
Запрос:
```sql
SELECT tuplePlus((1, 2), (2, 3));
```
Результат:
```text
┌─tuplePlus((1, 2), (2, 3))─┐
│ (3,5) │
└───────────────────────────┘
```
## tupleMinus {#tupleminus}
Вычисляет разность соответствующих значений двух кортежей одинакового размера.
**Синтаксис**
```sql
tupleMinus(tuple1, tuple2)
```
Синоним: `vectorDifference`.
**Аргументы**
- `tuple1` — первый кортеж. [Tuple](../../sql-reference/data-types/tuple.md).
- `tuple2` — второй кортеж. [Tuple](../../sql-reference/data-types/tuple.md).
**Возвращаемое значение**
- Кортеж с разностями.
Тип: [Tuple](../../sql-reference/data-types/tuple.md).
**Пример**
Запрос:
```sql
SELECT tupleMinus((1, 2), (2, 3));
```
Результат:
```text
┌─tupleMinus((1, 2), (2, 3))─┐
│ (-1,-1) │
└────────────────────────────┘
```
## tupleMultiply {#tuplemultiply}
Вычисляет произведение соответствующих значений двух кортежей одинакового размера.
**Синтаксис**
```sql
tupleMultiply(tuple1, tuple2)
```
**Аргументы**
- `tuple1` — первый кортеж. [Tuple](../../sql-reference/data-types/tuple.md).
- `tuple2` — второй кортеж. [Tuple](../../sql-reference/data-types/tuple.md).
**Возвращаемое значение**
- Кортеж с произведениями.
Тип: [Tuple](../../sql-reference/data-types/tuple.md).
**Пример**
Запрос:
```sql
SELECT tupleMultiply((1, 2), (2, 3));
```
Результат:
```text
┌─tupleMultiply((1, 2), (2, 3))─┐
│ (2,6) │
└───────────────────────────────┘
```
## tupleDivide {#tupledivide}
Вычисляет частное соответствующих значений двух кортежей одинакового размера. Обратите внимание, что при делении на ноль возвращается значение `inf`.
**Синтаксис**
```sql
tupleDivide(tuple1, tuple2)
```
**Аргументы**
- `tuple1` — первый кортеж. [Tuple](../../sql-reference/data-types/tuple.md).
- `tuple2` — второй кортеж. [Tuple](../../sql-reference/data-types/tuple.md).
**Возвращаемое значение**
- Кортеж с частными.
Тип: [Tuple](../../sql-reference/data-types/tuple.md).
**Пример**
Запрос:
```sql
SELECT tupleDivide((1, 2), (2, 3));
```
Результат:
```text
┌─tupleDivide((1, 2), (2, 3))─┐
│ (0.5,0.6666666666666666) │
└─────────────────────────────┘
```
## tupleNegate {#tuplenegate}
Применяет отрицание ко всем значениям кортежа.
**Синтаксис**
```sql
tupleNegate(tuple)
```
**Аргументы**
- `tuple` — кортеж. [Tuple](../../sql-reference/data-types/tuple.md).
**Возвращаемое значение**
- Кортеж с результатом отрицания.
Тип: [Tuple](../../sql-reference/data-types/tuple.md).
**Пример**
Запрос:
```sql
SELECT tupleNegate((1, 2));
```
Результат:
```text
┌─tupleNegate((1, 2))─┐
│ (-1,-2) │
└─────────────────────┘
```
## tupleMultiplyByNumber {#tuplemultiplybynumber}
Возвращает кортеж, в котором значения всех элементов умножены на заданное число.
**Синтаксис**
```sql
tupleMultiplyByNumber(tuple, number)
```
**Аргументы**
- `tuple` — кортеж. [Tuple](../../sql-reference/data-types/tuple.md).
- `number` — множитель. [Int/UInt](../../sql-reference/data-types/int-uint.md), [Float](../../sql-reference/data-types/float.md) или [Decimal](../../sql-reference/data-types/decimal.md).
**Возвращаемое значение**
- Кортеж с результатами умножения на число.
Тип: [Tuple](../../sql-reference/data-types/tuple.md).
**Пример**
Запрос:
```sql
SELECT tupleMultiplyByNumber((1, 2), -2.1);
```
Результат:
```text
┌─tupleMultiplyByNumber((1, 2), -2.1)─┐
│ (-2.1,-4.2) │
└─────────────────────────────────────┘
```
## tupleDivideByNumber {#tupledividebynumber}
Возвращает кортеж, в котором значения всех элементов поделены на заданное число. Обратите внимание, что при делении на ноль возвращается значение `inf`.
**Синтаксис**
```sql
tupleDivideByNumber(tuple, number)
```
**Аргументы**
- `tuple` — кортеж. [Tuple](../../sql-reference/data-types/tuple.md).
- `number` — делитель. [Int/UInt](../../sql-reference/data-types/int-uint.md), [Float](../../sql-reference/data-types/float.md) or [Decimal](../../sql-reference/data-types/decimal.md).
**Возвращаемое значение**
- Кортеж с результатами деления на число.
Тип: [Tuple](../../sql-reference/data-types/tuple.md).
**Пример**
Запрос:
```sql
SELECT tupleDivideByNumber((1, 2), 0.5);
```
Результат:
```text
┌─tupleDivideByNumber((1, 2), 0.5)─┐
│ (2,4) │
└──────────────────────────────────┘
```
## dotProduct {#dotproduct}
Вычисляет скалярное произведение двух кортежей одинакового размера.
**Синтаксис**
```sql
dotProduct(tuple1, tuple2)
```
Синоним: `scalarProduct`.
**Аргументы**
- `tuple1` — первый кортеж. [Tuple](../../sql-reference/data-types/tuple.md).
- `tuple2` — второй кортеж. [Tuple](../../sql-reference/data-types/tuple.md).
**Возвращаемое значение**
- Скалярное произведение.
Тип: [Int/UInt](../../sql-reference/data-types/int-uint.md), [Float](../../sql-reference/data-types/float.md) или [Decimal](../../sql-reference/data-types/decimal.md).
**Пример**
Запрос:
```sql
SELECT dotProduct((1, 2), (2, 3));
```
Результат:
```text
┌─dotProduct((1, 2), (2, 3))─┐
│ 8 │
└────────────────────────────┘
```
## L1Norm {#l1norm}
Вычисляет сумму абсолютных значений кортежа.
**Синтаксис**
```sql
L1Norm(tuple)
```
Синоним: `normL1`.
**Аргументы**
- `tuple` — кортеж. [Tuple](../../sql-reference/data-types/tuple.md).
**Возвращаемое значение**
- L1-норма или [расстояние городских кварталов](https://ru.wikipedia.org/wiki/%D0%A0%D0%B0%D1%81%D1%81%D1%82%D0%BE%D1%8F%D0%BD%D0%B8%D0%B5_%D0%B3%D0%BE%D1%80%D0%BE%D0%B4%D1%81%D0%BA%D0%B8%D1%85_%D0%BA%D0%B2%D0%B0%D1%80%D1%82%D0%B0%D0%BB%D0%BE%D0%B2).
Тип: [UInt](../../sql-reference/data-types/int-uint.md), [Float](../../sql-reference/data-types/float.md) или [Decimal](../../sql-reference/data-types/decimal.md).
**Пример**
Запрос:
```sql
SELECT L1Norm((1, 2));
```
Результат:
```text
┌─L1Norm((1, 2))─┐
│ 3 │
└────────────────┘
```
## L2Norm {#l2norm}
Вычисляет квадратный корень из суммы квадратов значений кортежа.
**Синтаксис**
```sql
L2Norm(tuple)
```
Синоним: `normL2`.
**Аргументы**
- `tuple` — кортеж. [Tuple](../../sql-reference/data-types/tuple.md).
**Возвращаемое значение**
- L2-норма или [Евклидово расстояние](https://ru.wikipedia.org/wiki/%D0%95%D0%B2%D0%BA%D0%BB%D0%B8%D0%B4%D0%BE%D0%B2%D0%B0_%D0%BC%D0%B5%D1%82%D1%80%D0%B8%D0%BA%D0%B0).
Тип: [Float](../../sql-reference/data-types/float.md).
**Пример**
Запрос:
```sql
SELECT L2Norm((1, 2));
```
Результат:
```text
┌───L2Norm((1, 2))─┐
│ 2.23606797749979 │
└──────────────────┘
```
## LinfNorm {#linfnorm}
Вычисляет максимум из абсолютных значений кортежа.
**Синтаксис**
```sql
LinfNorm(tuple)
```
Синоним: `normLinf`.
**Аргументы**
- `tuple` — кортеж. [Tuple](../../sql-reference/data-types/tuple.md).
**Возвращаемое значение**
- Linf-норма или максимальное абсолютное значение.
Тип: [Float](../../sql-reference/data-types/float.md).
**Пример**
Запрос:
```sql
SELECT LinfNorm((1, -2));
```
Результат:
```text
┌─LinfNorm((1, -2))─┐
│ 2 │
└───────────────────┘
```
## LpNorm {#lpnorm}
Возвращает корень степени `p` из суммы абсолютных значений кортежа, возведенных в степень `p`.
**Синтаксис**
```sql
LpNorm(tuple, p)
```
Синоним: `normLp`.
**Аргументы**
- `tuple` — кортеж. [Tuple](../../sql-reference/data-types/tuple.md).
- `p` — степень. Возможные значение: любое число из промежутка [1;inf). [UInt](../../sql-reference/data-types/int-uint.md) или [Float](../../sql-reference/data-types/float.md).
**Возвращаемое значение**
- [Lp-норма](https://ru.wikipedia.org/wiki/%D0%9D%D0%BE%D1%80%D0%BC%D0%B0_(%D0%BC%D0%B0%D1%82%D0%B5%D0%BC%D0%B0%D1%82%D0%B8%D0%BA%D0%B0)#%D0%9D%D0%B5%D0%BA%D0%BE%D1%82%D0%BE%D1%80%D1%8B%D0%B5_%D0%B2%D0%B8%D0%B4%D1%8B_%D0%BC%D0%B0%D1%82%D1%80%D0%B8%D1%87%D0%BD%D1%8B%D1%85_%D0%BD%D0%BE%D1%80%D0%BC)
Тип: [Float](../../sql-reference/data-types/float.md).
**Пример**
Запрос:
```sql
SELECT LpNorm((1, -2),2);
```
Результат:
```text
┌─LpNorm((1, -2), 2)─┐
│ 2.23606797749979 │
└────────────────────┘
```
## L1Distance {#l1distance}
Вычисляет расстояние между двумя точками (значения кортежей — координаты точек) в пространстве `L1` ([расстояние городских кварталов](https://ru.wikipedia.org/wiki/%D0%A0%D0%B0%D1%81%D1%81%D1%82%D0%BE%D1%8F%D0%BD%D0%B8%D0%B5_%D0%B3%D0%BE%D1%80%D0%BE%D0%B4%D1%81%D0%BA%D0%B8%D1%85_%D0%BA%D0%B2%D0%B0%D1%80%D1%82%D0%B0%D0%BB%D0%BE%D0%B2)).
**Синтаксис**
```sql
L1Distance(tuple1, tuple2)
```
Синоним: `distanceL1`.
**Аргументы**
- `tuple1` — первый кортеж. [Tuple](../../sql-reference/data-types/tuple.md).
- `tuple2` — второй кортеж. [Tuple](../../sql-reference/data-types/tuple.md).
**Возвращаемое значение**
- Расстояние в норме L1.
Тип: [Float](../../sql-reference/data-types/float.md).
**Пример**
Запрос:
```sql
SELECT L1Distance((1, 2), (2, 3));
```
Результат:
```text
┌─L1Distance((1, 2), (2, 3))─┐
│ 2 │
└────────────────────────────┘
```
## L2Distance {#l2distance}
Вычисляет расстояние между двумя точками (значения кортежей — координаты точек) в пространстве `L2` ([Евклидово расстояние](https://ru.wikipedia.org/wiki/%D0%95%D0%B2%D0%BA%D0%BB%D0%B8%D0%B4%D0%BE%D0%B2%D0%B0_%D0%BC%D0%B5%D1%82%D1%80%D0%B8%D0%BA%D0%B0)).
**Синтаксис**
```sql
L2Distance(tuple1, tuple2)
```
Синоним: `distanceL2`.
**Аргументы**
- `tuple1` — первый кортеж. [Tuple](../../sql-reference/data-types/tuple.md).
- `tuple2` — второй кортеж. [Tuple](../../sql-reference/data-types/tuple.md).
**Возвращаемое значение**
- Расстояние в норме L2.
Тип: [Float](../../sql-reference/data-types/float.md).
**Пример**
Запрос:
```sql
SELECT L2Distance((1, 2), (2, 3));
```
Результат:
```text
┌─L2Distance((1, 2), (2, 3))─┐
│ 1.4142135623730951 │
└────────────────────────────┘
```
## LinfDistance {#linfdistance}
Вычисляет расстояние между двумя точками (значения кортежей — координаты точек) в пространстве [`L_{inf}`](https://ru.wikipedia.org/wiki/%D0%9D%D0%BE%D1%80%D0%BC%D0%B0_(%D0%BC%D0%B0%D1%82%D0%B5%D0%BC%D0%B0%D1%82%D0%B8%D0%BA%D0%B0)#%D0%9D%D0%B5%D0%BA%D0%BE%D1%82%D0%BE%D1%80%D1%8B%D0%B5_%D0%B2%D0%B8%D0%B4%D1%8B_%D0%BC%D0%B0%D1%82%D1%80%D0%B8%D1%87%D0%BD%D1%8B%D1%85_%D0%BD%D0%BE%D1%80%D0%BC).
**Синтаксис**
```sql
LinfDistance(tuple1, tuple2)
```
Синоним: `distanceLinf`.
**Аргументы**
- `tuple1` — первый кортеж. [Tuple](../../sql-reference/data-types/tuple.md).
- `tuple2` — второй кортеж. [Tuple](../../sql-reference/data-types/tuple.md).
**Возвращаемые значения**
- Расстояние в норме Linf.
Тип: [Float](../../sql-reference/data-types/float.md).
**Пример**
Запрос:
```sql
SELECT LinfDistance((1, 2), (2, 3));
```
Результат:
```text
┌─LinfDistance((1, 2), (2, 3))─┐
│ 1 │
└──────────────────────────────┘
```
## LpDistance {#lpdistance}
Вычисляет расстояние между двумя точками (значения кортежей — координаты точек) в пространстве [`Lp`](https://ru.wikipedia.org/wiki/%D0%9D%D0%BE%D1%80%D0%BC%D0%B0_(%D0%BC%D0%B0%D1%82%D0%B5%D0%BC%D0%B0%D1%82%D0%B8%D0%BA%D0%B0)#%D0%9D%D0%B5%D0%BA%D0%BE%D1%82%D0%BE%D1%80%D1%8B%D0%B5_%D0%B2%D0%B8%D0%B4%D1%8B_%D0%BC%D0%B0%D1%82%D1%80%D0%B8%D1%87%D0%BD%D1%8B%D1%85_%D0%BD%D0%BE%D1%80%D0%BC).
**Синтаксис**
```sql
LpDistance(tuple1, tuple2, p)
```
Синоним: `distanceLp`.
**Аргументы**
- `tuple1` — первый кортеж. [Tuple](../../sql-reference/data-types/tuple.md).
- `tuple2` — второй кортеж. [Tuple](../../sql-reference/data-types/tuple.md).
- `p` — степень. Возможные значение: любое число из промежутка [1;inf). [UInt](../../sql-reference/data-types/int-uint.md) или [Float](../../sql-reference/data-types/float.md).
**Возвращаемое значение**
- Расстояние в норме Lp.
Тип: [Float](../../sql-reference/data-types/float.md).
**Пример**
Запрос:
```sql
SELECT LpDistance((1, 2), (2, 3), 3);
```
Результат:
```text
┌─LpDistance((1, 2), (2, 3), 3)─┐
│ 1.2599210498948732 │
└───────────────────────────────┘
```
## L1Normalize {#l1normalize}
Вычисляет единичный вектор для исходного вектора (значения кортежа — координаты вектора) в пространстве `L1` ([расстояние городских кварталов](https://ru.wikipedia.org/wiki/%D0%A0%D0%B0%D1%81%D1%81%D1%82%D0%BE%D1%8F%D0%BD%D0%B8%D0%B5_%D0%B3%D0%BE%D1%80%D0%BE%D0%B4%D1%81%D0%BA%D0%B8%D1%85_%D0%BA%D0%B2%D0%B0%D1%80%D1%82%D0%B0%D0%BB%D0%BE%D0%B2)).
**Синтаксис**
```sql
L1Normalize(tuple)
```
Синоним: `normalizeL1`.
**Аргументы**
- `tuple` — [Tuple](../../sql-reference/data-types/tuple.md).
**Возвращаемое значение**
- Единичный вектор.
Тип: кортеж [Tuple](../../sql-reference/data-types/tuple.md) значений [Float](../../sql-reference/data-types/float.md).
**Пример**
Запрос:
```sql
SELECT L1Normalize((1, 2));
```
Результат:
```text
┌─L1Normalize((1, 2))─────────────────────┐
│ (0.3333333333333333,0.6666666666666666) │
└─────────────────────────────────────────┘
```
## L2Normalize {#l2normalize}
Вычисляет единичный вектор для исходного вектора (значения кортежа — координаты вектора) в пространстве `L2` ([Евклидово пространство](https://ru.wikipedia.org/wiki/%D0%95%D0%B2%D0%BA%D0%BB%D0%B8%D0%B4%D0%BE%D0%B2%D0%BE_%D0%BF%D1%80%D0%BE%D1%81%D1%82%D1%80%D0%B0%D0%BD%D1%81%D1%82%D0%B2%D0%BE).
**Синтаксис**
```sql
L2Normalize(tuple)
```
Синоним: `normalizeL1`.
**Аргументы**
- `tuple` — кортеж. [Tuple](../../sql-reference/data-types/tuple.md).
**Возвращаемое значение**
- Единичный вектор.
Тип: кортеж [Tuple](../../sql-reference/data-types/tuple.md) значений [Float](../../sql-reference/data-types/float.md).
**Пример**
Запрос:
```sql
SELECT L2Normalize((3, 4));
```
Результат:
```text
┌─L2Normalize((3, 4))─┐
│ (0.6,0.8) │
└─────────────────────┘
```
## LinfNormalize {#linfnormalize}
Вычисляет единичный вектор для исходного вектора (значения кортежа — координаты вектора) в пространстве [`L_{inf}`](https://ru.wikipedia.org/wiki/%D0%9D%D0%BE%D1%80%D0%BC%D0%B0_(%D0%BC%D0%B0%D1%82%D0%B5%D0%BC%D0%B0%D1%82%D0%B8%D0%BA%D0%B0)#%D0%9D%D0%B5%D0%BA%D0%BE%D1%82%D0%BE%D1%80%D1%8B%D0%B5_%D0%B2%D0%B8%D0%B4%D1%8B_%D0%BC%D0%B0%D1%82%D1%80%D0%B8%D1%87%D0%BD%D1%8B%D1%85_%D0%BD%D0%BE%D1%80%D0%BC).
**Синтаксис**
```sql
LinfNormalize(tuple)
```
Синоним: `normalizeLinf `.
**Аргументы**
- `tuple` — кортеж. [Tuple](../../sql-reference/data-types/tuple.md).
**Возвращаемое значение**
- Единичный вектор.
Тип: кортеж [Tuple](../../sql-reference/data-types/tuple.md) значений [Float](../../sql-reference/data-types/float.md).
**Пример**
Запрос:
```sql
SELECT LinfNormalize((3, 4));
```
Результат:
```text
┌─LinfNormalize((3, 4))─┐
│ (0.75,1) │
└───────────────────────┘
```
## LpNormalize {#lpnormalize}
Вычисляет единичный вектор для исходного вектора (значения кортежа — координаты вектора) в пространстве [`Lp`](https://ru.wikipedia.org/wiki/%D0%9D%D0%BE%D1%80%D0%BC%D0%B0_(%D0%BC%D0%B0%D1%82%D0%B5%D0%BC%D0%B0%D1%82%D0%B8%D0%BA%D0%B0)#%D0%9D%D0%B5%D0%BA%D0%BE%D1%82%D0%BE%D1%80%D1%8B%D0%B5_%D0%B2%D0%B8%D0%B4%D1%8B_%D0%BC%D0%B0%D1%82%D1%80%D0%B8%D1%87%D0%BD%D1%8B%D1%85_%D0%BD%D0%BE%D1%80%D0%BC).
**Синтаксис**
```sql
LpNormalize(tuple, p)
```
Синоним: `normalizeLp `.
**Аргументы**
- `tuple` — кортеж. [Tuple](../../sql-reference/data-types/tuple.md).
- `p` — степень. Возможные значение: любое число из промежутка [1;inf). [UInt](../../sql-reference/data-types/int-uint.md) или [Float](../../sql-reference/data-types/float.md).
**Возвращаемое значение**
- Единичный вектор.
Тип: кортеж [Tuple](../../sql-reference/data-types/tuple.md) значений [Float](../../sql-reference/data-types/float.md).
**Пример**
Запрос:
```sql
SELECT LpNormalize((3, 4),5);
```
Результат:
```text
┌─LpNormalize((3, 4), 5)──────────────────┐
│ (0.7187302630182624,0.9583070173576831) │
└─────────────────────────────────────────┘
```
## cosineDistance {#cosinedistance}
Вычисляет косинусную разницу двух векторов (значения кортежей — координаты векторов). Чем меньше возвращаемое значение, тем больше сходство между векторами.
**Синтаксис**
```sql
cosineDistance(tuple1, tuple2)
```
**Аргументы**
- `tuple1` — первый кортеж. [Tuple](../../sql-reference/data-types/tuple.md).
- `tuple2` — второй кортеж. [Tuple](../../sql-reference/data-types/tuple.md).
**Возвращаемые значения**
- Разность между единицей и косинуса угла между векторами.
Тип: [Float](../../sql-reference/data-types/float.md).
**Пример**
Запрос:
```sql
SELECT cosineDistance((1, 2), (2, 3));
```
Результат:
```text
┌─cosineDistance((1, 2), (2, 3))─┐
│ 0.007722123286332261 │
└────────────────────────────────┘
```

View File

@ -18,20 +18,30 @@ toc_title: "Операторы"
`-a` - функция `negate(a)`.
Для чисел в кортеже также может быть использована [tupleNegate](../../sql-reference/functions/tuple-functions.md#tuplenegate).
## Операторы умножения и деления {#operatory-umnozheniia-i-deleniia}
`a * b` - функция `multiply(a, b)`
Для умножения кортежа на число также может быть использована [tupleMultiplyByNumber](../../sql-reference/functions/tuple-functions.md#tuplemultiplybynumber), для скалярного произведения: [dotProduct](../../sql-reference/functions/tuple-functions.md#dotproduct).
`a / b` - функция `divide(a, b)`
Для деления кортежа на число также может быть использована [tupleDivideByNumber](../../sql-reference/functions/tuple-functions.md#tupledividebynumber).
`a % b` - функция `modulo(a, b)`
## Операторы сложения и вычитания {#operatory-slozheniia-i-vychitaniia}
`a + b` - функция `plus(a, b)`
Для сложения кортежей также может быть использована [tuplePlus](../../sql-reference/functions/tuple-functions.md#tupleplus).
`a - b` - функция `minus(a, b)`
Для вычитания кортежей также может быть использована [tupleMinus](../../sql-reference/functions/tuple-functions.md#tupleminus).
## Операторы сравнения {#operatory-sravneniia}
`a = b` - функция `equals(a, b)`
@ -72,6 +82,53 @@ toc_title: "Операторы"
`a GLOBAL NOT IN ...` - функция `globalNotIn(a, b)`
`a = ANY (subquery)` функция `in(a, subquery)`.
`a != ANY (subquery)` равнозначно `a NOT IN (SELECT singleValueOrNull(*) FROM subquery)`.
`a = ALL (subquery)` равнозначно `a IN (SELECT singleValueOrNull(*) FROM subquery)`.
`a != ALL (subquery)` функция `notIn(a, subquery)`.
**Примеры**
Запрос с ALL:
``` sql
SELECT number AS a FROM numbers(10) WHERE a > ALL (SELECT number FROM numbers(3, 3));
```
Результат:
``` text
┌─a─┐
│ 6 │
│ 7 │
│ 8 │
│ 9 │
└───┘
```
Запрос с ANY:
``` sql
SELECT number AS a FROM numbers(10) WHERE a > ANY (SELECT number FROM numbers(3, 3));
```
Результат:
``` text
┌─a─┐
│ 4 │
│ 5 │
│ 6 │
│ 7 │
│ 8 │
│ 9 │
└───┘
```
## Оператор для работы с датами и временем {#operators-datetime}
### EXTRACT {#extract}

View File

@ -15,6 +15,7 @@ CREATE USER [IF NOT EXISTS | OR REPLACE] name1 [ON CLUSTER cluster_name1]
[NOT IDENTIFIED | IDENTIFIED {[WITH {no_password | plaintext_password | sha256_password | sha256_hash | double_sha1_password | double_sha1_hash}] BY {'password' | 'hash'}} | {WITH ldap SERVER 'server_name'} | {WITH kerberos [REALM 'realm']}]
[HOST {LOCAL | NAME 'name' | REGEXP 'name_regexp' | IP 'address' | LIKE 'pattern'} [,...] | ANY | NONE]
[DEFAULT ROLE role [,...]]
[DEFAULT DATABASE database | NONE]
[GRANTEES {user | role | ANY | NONE} [,...] [EXCEPT {user | role} [,...]]]
[SETTINGS variable [= value] [MIN [=] min_value] [MAX [=] max_value] [READONLY | WRITABLE] | PROFILE 'profile_name'] [,...]
```

View File

@ -121,3 +121,14 @@ INSERT INTO [db.]table [(c1, c2, c3)] SELECT ...
- Данные поступают в режиме реального времени.
- Вы загружаете данные, которые как правило отсортированы по времени.
Также возможно вставлять данные асинхронно во множественных маленьких вставках. Данные от таких вставок сначала собираются в пачки, а потом вставляются в таблицу. Чтобы включить асинхронный режим, используйте настройку [async_insert](../../operations/settings/settings.md#async-insert). Обратите внимание, что асинхронные вставки поддерживаются только через протокол HTTP, а дедупликация при этом не производится.
**См. также**
- [async_insert](../../operations/settings/settings.md#async-insert)
- [async_insert_threads](../../operations/settings/settings.md#async-insert-threads)
- [wait_for_async_insert](../../operations/settings/settings.md#wait-for-async-insert)
- [wait_for_async_insert_timeout](../../operations/settings/settings.md#wait-for-async-insert-timeout)
- [async_insert_max_data_size](../../operations/settings/settings.md#async-insert-max-data-size)
- [async_insert_busy_timeout_ms](../../operations/settings/settings.md#async-insert-busy-timeout-ms)
- [async_insert_stale_timeout_ms](../../operations/settings/settings.md#async-insert-stale-timeout-ms)

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@ -0,0 +1,69 @@
---
toc_title: EXCEPT
---
# Секция EXCEPT {#except-clause}
`EXCEPT` возвращает только те строки, которые являются результатом первого запроса без результатов второго. В запросах количество, порядок следования и типы столбцов должны совпадать. Результат `EXCEPT` может содержать повторяющиеся строки.
Если используется несколько `EXCEPT`, и в выражении не указаны скобки, `EXCEPT` выполняется по порядку слева направо. `EXCEPT` имеет такой же приоритет выполнения, как `UNION`, и приоритет ниже, чем у `INTERSECT`.
``` sql
SELECT column1 [, column2 ]
FROM table1
[WHERE condition]
EXCEPT
SELECT column1 [, column2 ]
FROM table2
[WHERE condition]
```
Условие в секции `WHERE` может быть любым в зависимости от ваших требований.
**Примеры**
Запрос:
``` sql
SELECT number FROM numbers(1,10) EXCEPT SELECT number FROM numbers(3,6);
```
Результат:
``` text
┌─number─┐
│ 1 │
│ 2 │
│ 9 │
│ 10 │
└────────┘
```
Запрос:
``` sql
CREATE TABLE t1(one String, two String, three String) ENGINE=Memory();
CREATE TABLE t2(four String, five String, six String) ENGINE=Memory();
INSERT INTO t1 VALUES ('q', 'm', 'b'), ('s', 'd', 'f'), ('l', 'p', 'o'), ('s', 'd', 'f'), ('s', 'd', 'f'), ('k', 't', 'd'), ('l', 'p', 'o');
INSERT INTO t2 VALUES ('q', 'm', 'b'), ('b', 'd', 'k'), ('s', 'y', 't'), ('s', 'd', 'f'), ('m', 'f', 'o'), ('k', 'k', 'd');
SELECT * FROM t1 EXCEPT SELECT * FROM t2;
```
Результат:
``` text
┌─one─┬─two─┬─three─┐
│ l │ p │ o │
│ k │ t │ d │
│ l │ p │ o │
└─────┴─────┴───────┘
```
**См. также**
- [UNION](union.md#union-clause)
- [INTERSECT](intersect.md#intersect-clause)

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@ -45,8 +45,10 @@ SELECT [DISTINCT [ON (column1, column2, ...)]] expr_list
- [Секция LIMIT BY](limit-by.md)
- [Секция HAVING](having.md)
- [Секция LIMIT](limit.md)
[Секция OFFSET](offset.md)
- [Секция OFFSET](offset.md)
- [Секция UNION ALL](union.md)
- [Секция INTERSECT](intersect.md)
- [Секция EXCEPT](except.md)
- [Секция INTO OUTFILE](into-outfile.md)
- [Секция FORMAT](format.md)

View File

@ -0,0 +1,73 @@
---
toc_title: INTERSECT
---
# Секция INTERSECT {#intersect-clause}
`INTERSECT` возвращает строки, которые есть только в результатах первого и второго запросов. В запросах должны совпадать количество столбцов, их порядок и тип. Результат `INTERSECT` может содержать повторяющиеся строки.
Если используется несколько `INTERSECT` и скобки не указаны, пересечение выполняется слева направо. У `INTERSECT` более высокий приоритет выполнения, чем у `UNION` и `EXCEPT`.
``` sql
SELECT column1 [, column2 ]
FROM table1
[WHERE condition]
INTERSECT
SELECT column1 [, column2 ]
FROM table2
[WHERE condition]
```
Условие может быть любым в зависимости от ваших требований.
**Примеры**
Запрос:
``` sql
SELECT number FROM numbers(1,10) INTERSECT SELECT number FROM numbers(3,6);
```
Результат:
``` text
┌─number─┐
│ 3 │
│ 4 │
│ 5 │
│ 6 │
│ 7 │
│ 8 │
└────────┘
```
Запрос:
``` sql
CREATE TABLE t1(one String, two String, three String) ENGINE=Memory();
CREATE TABLE t2(four String, five String, six String) ENGINE=Memory();
INSERT INTO t1 VALUES ('q', 'm', 'b'), ('s', 'd', 'f'), ('l', 'p', 'o'), ('s', 'd', 'f'), ('s', 'd', 'f'), ('k', 't', 'd'), ('l', 'p', 'o');
INSERT INTO t2 VALUES ('q', 'm', 'b'), ('b', 'd', 'k'), ('s', 'y', 't'), ('s', 'd', 'f'), ('m', 'f', 'o'), ('k', 'k', 'd');
SELECT * FROM t1 INTERSECT SELECT * FROM t2;
```
Результат:
``` text
┌─one─┬─two─┬─three─┐
│ q │ m │ b │
│ s │ d │ f │
│ s │ d │ f │
│ s │ d │ f │
└─────┴─────┴───────┘
```
**См. также**
- [UNION](union.md#union-clause)
- [EXCEPT](except.md#except-clause)

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@ -1 +0,0 @@
../../en/development/continuous-integration.md

View File

@ -0,0 +1,155 @@
# 持续集成检查 {#continuous-integration-checks}
当你提交一个pull请求时, ClickHouse[持续集成(CI)系统](https://clickhouse.com/docs/en/development/tests/#test-automation)会对您的代码运行一些自动检查.
这在存储库维护者(来自ClickHouse团队的人)筛选了您的代码并将可测试标签添加到您的pull请求之后发生.
检查的结果被列在[GitHub检查文档](https://docs.github.com/en/github/collaborating-with-pull-requests/collaborating-on-repositories-with-code-quality-features/about-status-checks)中所述的GitHub pull请求页面.
如果检查失败,您可能被要求去修复它. 该界面介绍了您可能遇到的检查,以及如何修复它们.
如果检查失败看起来与您的更改无关, 那么它可能是一些暂时的故障或基础设施问题. 向pull请求推一个空的commit以重新启动CI检查:
```
git reset
git commit --allow-empty
git push
```
如果您不确定要做什么,可以向维护人员寻求帮助.
## 与Master合并 {#merge-with-master}
验证PR是否可以合并到master. 如果没有, 它将失败并显示消息'Cannot fetch mergecommit'的.请按[GitHub文档](https://docs.github.com/en/github/collaborating-with-pull-requests/addressing-merge-conflicts/resolving-a-merge-conflict-on-github)中描述的冲突解决, 或使用git将主分支合并到您的pull请求分支来修复这个检查.
## 文档检查 {#docs-check}
尝试构建ClickHouse文档网站. 如果您更改了文档中的某些内容, 它可能会失败. 最可能的原因是文档中的某些交叉链接是错误的. 转到检查报告并查找`ERROR`和`WARNING`消息.
### 报告详情 {#report-details}
- [状态页示例](https://clickhouse-test-reports.s3.yandex.net/12550/eabcc293eb02214caa6826b7c15f101643f67a6b/docs_check.html)
- `docs_output.txt`包含构建日志信息. [成功结果案例](https://clickhouse-test-reports.s3.yandex.net/12550/eabcc293eb02214caa6826b7c15f101643f67a6b/docs_check/docs_output.txt)
## 描述信息检查 {#description-check}
检查pull请求的描述是否符合[PULL_REQUEST_TEMPLATE.md](https://github.com/ClickHouse/ClickHouse/blob/master/.github/PULL_REQUEST_TEMPLATE.md)模板.
您必须为您的更改指定一个更改日志类别(例如Bug修复), 并且为[CHANGELOG.md](../whats-new/changelog/)编写一条用户可读的消息用来描述更改.
## 推送到DockerHub {#push-to-dockerhub}
生成用于构建和测试的docker映像, 然后将它们推送到DockerHub.
## 标记检查 {#marker-check}
该检查意味着CI系统已经开始处理PR.当它处于'待处理'状态时,意味着尚未开始所有检查. 启动所有检查后,状态更改为'成功'.
# 格式检查 {#style-check}
使用`utils/check-style/check-style`二进制文件执行一些简单的基于正则表达式的代码样式检查(注意, 它可以在本地运行).
如果失败, 按照[代码样式指南](./style.md)修复样式错误.
### 报告详情 {#report-details}
- [状态页示例](https://clickhouse-test-reports.s3.yandex.net/12550/659c78c7abb56141723af6a81bfae39335aa8cb2/style_check.html)
- `docs_output.txt`记录了查结果错误(无效表格等), 空白页表示没有错误. [成功结果案例](https://clickhouse-test-reports.s3.yandex.net/12550/659c78c7abb56141723af6a81bfae39335aa8cb2/style_check/output.txt)
### PVS 检查 {#pvs-check}
使用静态分析工具[PVS-studio](https://www.viva64.com/en/pvs-studio/)检查代码. 查看报告以查看确切的错误.如果可以则修复它们, 如果不行, 可以向ClickHouse的维护人员寻求帮忙.
### 报告详情 {#report-details}
- [状态页示例](https://clickhouse-test-reports.s3.yandex.net/12550/67d716b5cc3987801996c31a67b31bf141bc3486/pvs_check.html)
- `test_run.txt.out.log`包含构建和分析日志文件.它只包含解析或未找到的错误.
- `HTML report`包含分析结果.有关说明请访问PVS的[官方网站](https://www.viva64.com/en/m/0036/#ID14E9A2B2CD)
## 快速测试 {#fast-test}
通常情况下这是PR运行的第一个检查.它构建ClickHouse以及大多数无状态运行测试, 其中省略了一些.如果失败,在修复之前不会开始进一步的检查. 查看报告以了解哪些测试失败, 然后按照[此处](./tests.md#functional-test-locally)描述的在本地重现失败.
### 报告详情 {#report-details}
[状态页示例](https://clickhouse-test-reports.s3.yandex.net/12550/67d716b5cc3987801996c31a67b31bf141bc3486/fast_test.html)
#### 状态页文件 {#status-page-files}
- `runlog.out.log` 是包含所有其他日志的通用日志.
- `test_log.txt`
- `submodule_log.txt` 包含关于克隆和检查所需子模块的消息.
- `stderr.log`
- `stdout.log`
- `clickhouse-server.log`
- `clone_log.txt`
- `install_log.txt`
- `clickhouse-server.err.log`
- `build_log.txt`
- `cmake_log.txt` 包含关于C/C++和Linux标志检查的消息.
#### 状态页列信息 {#status-page-columns}
- 测试名称 -- 包含测试的名称(不带路径, 例如, 所有类型的测试将被剥离到该名称).
- 测试状态 -- 跳过、成功或失败之一.
- 测试时间, 秒. -- 这个测试是空的.
## 建构检查 {#build-check}
在各种配置中构建ClickHouse, 以便在后续步骤中使用. 您必须修复失败的构建.构建日志通常有足够的信息来修复错误, 但是您可能必须在本地重现故障. `cmake`选项可以在构建日志中通过grep `cmake`操作找到.使用这些选项并遵循[一般的构建过程](./build.md).
### 报告详情 {#report-details}
[状态页示例](https://clickhouse-builds.s3.yandex.net/12550/67d716b5cc3987801996c31a67b31bf141bc3486/clickhouse_build_check/report.html)
- **Compiler**: `gcc-9``clang-10` (或其他架构的`clang-10-xx`, 比如`clang-10-freebsd`).
- **Build type**: `Debug` or `RelWithDebInfo` (cmake).
- **Sanitizer**: `none` (without sanitizers), `address` (ASan), `memory` (MSan), `undefined` (UBSan), or `thread` (TSan).
- **Bundled**: `bundled` 构建使用来自 `contrib` 库, 而 `unbundled` 构建使用系统库.
- **Splitted**: `splitted` is a [split build](https://clickhouse.com/docs/en/development/build/#split-build)
- **Status**: `成功``失败`
- **Build log**: 链接到构建和文件复制日志, 当构建失败时很有用.
- **Build time**.
- **Artifacts**: 构建结果文件 (`XXX`是服务器版本, 比如`20.8.1.4344`).
- `clickhouse-client_XXX_all.deb`
-` clickhouse-common-static-dbg_XXX[+asan, +msan, +ubsan, +tsan]_amd64.deb`
- `clickhouse-common-staticXXX_amd64.deb`
- `clickhouse-server_XXX_all.deb`
- `clickhouse-test_XXX_all.deb`
- `clickhouse_XXX_amd64.buildinfo`
- `clickhouse_XXX_amd64.changes`
- `clickhouse`: Main built binary.
- `clickhouse-odbc-bridge`
- `unit_tests_dbms`: 带有 ClickHouse 单元测试的 GoogleTest 二进制文件.
- `shared_build.tgz`: 使用共享库构建.
- `performance.tgz`: 用于性能测试的特殊包.
## 特殊构建检查 {#special-buildcheck}
使用clang-tidy执行静态分析和代码样式检查. 该报告类似于构建检查. 修复在构建日志中发现的错误.
## 功能无状态测试 {#functional-stateless-tests}
为构建在不同配置中的ClickHouse二进制文件运行[无状态功能测试](./tests.md#functional-tests)——发布、调试、使用杀毒软件等.通过报告查看哪些测试失败,然后按照[此处](./tests.md#functional-test-locally)描述的在本地重现失败.注意, 您必须使用正确的构建配置来重现——在AddressSanitizer下测试可能失败,但在Debug中可以通过.从[CI构建检查页面](./build.md#you-dont-have-to-build-clickhouse)下载二进制文件, 或者在本地构建它.
## 功能有状态测试 {#functional-stateful-tests}
运行[有状态功能测试](./tests.md#functional-tests).以无状态功能测试相同的方式对待它们.不同之处在于它们需要从[Yandex.Metrica数据集](https://clickhouse.com/docs/en/getting-started/example-datasets/metrica/)的`hits`和`visits`表来运行.
## 集成测试 {#integration-tests}
运行[集成测试](./tests.md#integration-tests).
## Testflows 检查{#testflows-check}
使用Testflows测试系统去运行一些测试, 在[此处](https://github.com/ClickHouse/ClickHouse/tree/master/tests/testflows#running-tests-locally)查看如何在本地运行它们.
## 压力测试 {#stress-test}
从多个客户端并发运行无状态功能测试, 用以检测与并发相关的错误.如果失败:
```
* Fix all other test failures first;
* Look at the report to find the server logs and check them for possible causes
of error.
```
## 冒烟测试 {#split-build-smoke-test}
检查[拆分构建](./build.md#split-build)配置中的服务器构建是否可以启动并运行简单查询.如果失败:
```
* Fix other test errors first;
* Build the server in [split build](./build.md#split-build) configuration
locally and check whether it can start and run `select 1`.
```
## 兼容性检查 {#compatibility-check}
检查`clickhouse`二进制文件是否可以在带有旧libc版本的发行版上运行.如果失败, 请向维护人员寻求帮助.
## AST模糊器 {#ast-fuzzer}
运行随机生成的查询来捕获程序错误.如果失败, 请向维护人员寻求帮助.
## 性能测试 {#performance-tests}
测量查询性能的变化. 这是最长的检查, 只需不到 6 小时即可运行.性能测试报告在[此处](https://github.com/ClickHouse/ClickHouse/tree/master/docker/test/performance-comparison#how-to-read-the-report)有详细描述.
## 质量保证 {#qa}
什么是状态页面上的任务(专用网络)项目?
它是 Yandex 内部工作系统的链接. Yandex 员工可以看到检查的开始时间及其更详细的状态.
运行测试的地方
Yandex 内部基础设施的某个地方.

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@ -1 +0,0 @@
../../../en/operations/external-authenticators/kerberos.md

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@ -0,0 +1,105 @@
# Kerberos认证 {#external-authenticators-kerberos}
现有正确配置的 ClickHouse 用户可以通过 Kerberos 身份验证协议进行身份验证.
目前, Kerberos 只能用作现有用户的外部身份验证器,这些用户在 `users.xml` 或本地访问控制路径中定义.
这些用户只能使用 HTTP 请求, 并且必须能够使用 GSS-SPNEGO 机制进行身份验证.
对于这种方法, 必须在系统中配置 Kerberos, 且必须在 ClickHouse 配置中启用.
## 开启Kerberos {#enabling-kerberos-in-clickHouse}
要启用 Kerberos, 应该在 `config.xml` 中包含 `kerberos` 部分. 此部分可能包含其他参数.
#### 参数: {#parameters}
- `principal` - 将在接受安全上下文时获取和使用的规范服务主体名称.
- 此参数是可选的, 如果省略, 将使用默认主体.
- `realm` - 一个领域, 用于将身份验证限制为仅那些发起者领域与其匹配的请求.
- 此参数是可选的,如果省略,则不会应用其他领域的过滤.
示例 (进入 `config.xml`):
```xml
<yandex>
<!- ... -->
<kerberos />
</yandex>
```
主体规范:
```xml
<yandex>
<!- ... -->
<kerberos>
<principal>HTTP/clickhouse.example.com@EXAMPLE.COM</principal>
</kerberos>
</yandex>
```
按领域过滤:
```xml
<yandex>
<!- ... -->
<kerberos>
<realm>EXAMPLE.COM</realm>
</kerberos>
</yandex>
```
!!! warning "注意"
您只能定义一个 `kerberos` 部分. 多个 `kerberos` 部分的存在将强制 ClickHouse 禁用 Kerberos 身份验证.
!!! warning "注意"
`主体`和`领域`部分不能同时指定. `主体`和`领域`的出现将迫使ClickHouse禁用Kerberos身份验证.
## Kerberos作为现有用户的外部身份验证器 {#kerberos-as-an-external-authenticator-for-existing-users}
Kerberos可以用作验证本地定义用户(在`users.xml`或本地访问控制路径中定义的用户)身份的方法。目前,**只有**通过HTTP接口的请求才能被认证(通过GSS-SPNEGO机制).
Kerberos主体名称格式通常遵循以下模式:
- *primary/instance@REALM*
*/instance* 部分可能出现零次或多次. **发起者的规范主体名称的主要部分应与被认证用户名匹配, 以便身份验证成功**.
### `users.xml`中启用Kerberos {#enabling-kerberos-in-users-xml}
为了启用用户的 Kerberos 身份验证, 请在用户定义中指定 `kerberos` 部分而不是`密码`或类似部分.
参数:
- `realm` - 用于将身份验证限制为仅那些发起者的领域与其匹配的请求的领域.
- 此参数是可选的, 如果省略, 则不会应用其他按领域的过滤.
示例 (进入 `users.xml`):
```
<yandex>
<!- ... -->
<users>
<!- ... -->
<my_user>
<!- ... -->
<kerberos>
<realm>EXAMPLE.COM</realm>
</kerberos>
</my_user>
</users>
</yandex>
```
!!! warning "警告"
注意, Kerberos身份验证不能与任何其他身份验证机制一起使用. 任何其他部分(如`密码`和`kerberos`)的出现都会迫使ClickHouse关闭.
!!! info "提醒"
请注意, 现在, 一旦用户 `my_user` 使用 `kerberos`, 必须在主 `config.xml` 文件中启用 Kerberos如前所述.
### 使用 SQL 启用 Kerberos {#enabling-kerberos-using-sql}
在 ClickHouse 中启用 [SQL 驱动的访问控制和帐户管理](https://clickhouse.com/docs/en/operations/access-rights/#access-control)后, 也可以使用 SQL 语句创建由 Kerberos 识别的用户.
```sql
CREATE USER my_user IDENTIFIED WITH kerberos REALM 'EXAMPLE.COM'
```
...或者, 不按领域过滤:
```sql
CREATE USER my_user IDENTIFIED WITH kerberos
```

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@ -5,4 +5,34 @@ machine_translated_rev: 5decc73b5dc60054f19087d3690c4eb99446a6c3
## system.asynchronous_metric_log {#system-tables-async-log}
包含以下内容的历史值 `system.asynchronous_log` (见 [系统。asynchronous_metrics](../../operations/system-tables/asynchronous_metrics.md#system_tables-asynchronous_metrics))
包含每分钟记录一次的 `system.asynchronous_metrics`历史值. 默认开启.
列:
- `event_date` ([Date](../../sql-reference/data-types/date.md)) — 事件日期.
- `event_time` ([DateTime](../../sql-reference/data-types/datetime.md)) — 事件时间.
- `event_time_microseconds` ([DateTime64](../../sql-reference/data-types/datetime64.md)) — 事件时间(微秒).
- `name` ([String](../../sql-reference/data-types/string.md)) — 指标名.
- `value` ([Float64](../../sql-reference/data-types/float.md)) — 指标值.
**示例**
``` sql
SELECT * FROM system.asynchronous_metric_log LIMIT 10
```
``` text
┌─event_date─┬──────────event_time─┬────event_time_microseconds─┬─name─────────────────────────────────────┬─────value─┐
│ 2020-09-05 │ 2020-09-05 15:56:30 │ 2020-09-05 15:56:30.025227 │ CPUFrequencyMHz_0 │ 2120.9 │
│ 2020-09-05 │ 2020-09-05 15:56:30 │ 2020-09-05 15:56:30.025227 │ jemalloc.arenas.all.pmuzzy │ 743 │
│ 2020-09-05 │ 2020-09-05 15:56:30 │ 2020-09-05 15:56:30.025227 │ jemalloc.arenas.all.pdirty │ 26288 │
│ 2020-09-05 │ 2020-09-05 15:56:30 │ 2020-09-05 15:56:30.025227 │ jemalloc.background_thread.run_intervals │ 0 │
│ 2020-09-05 │ 2020-09-05 15:56:30 │ 2020-09-05 15:56:30.025227 │ jemalloc.background_thread.num_runs │ 0 │
│ 2020-09-05 │ 2020-09-05 15:56:30 │ 2020-09-05 15:56:30.025227 │ jemalloc.retained │ 60694528 │
│ 2020-09-05 │ 2020-09-05 15:56:30 │ 2020-09-05 15:56:30.025227 │ jemalloc.mapped │ 303161344 │
│ 2020-09-05 │ 2020-09-05 15:56:30 │ 2020-09-05 15:56:30.025227 │ jemalloc.resident │ 260931584 │
│ 2020-09-05 │ 2020-09-05 15:56:30 │ 2020-09-05 15:56:30.025227 │ jemalloc.metadata │ 12079488 │
│ 2020-09-05 │ 2020-09-05 15:56:30 │ 2020-09-05 15:56:30.025227 │ jemalloc.allocated │ 133756128 │
└────────────┴─────────────────────┴────────────────────────────┴──────────────────────────────────────────┴───────────┘
```
**另请参阅**
- [system.asynchronous_metrics](../../operations/system-tables/asynchronous_metrics.md#system_tables-asynchronous_metrics) — 包含在后台定期计算的指标.
- [system.metric_log](../../operations/system-tables/metric_log.md#system_tables-metric_log) — 包含定期刷新到磁盘表 `system.metrics` 以及 `system.events` 中的指标值历史记录.

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@ -71,7 +71,7 @@ echo 4096 | sudo tee /sys/block/md2/md/stripe_cache_size
## 文件系统 {#file-system}
Ext4是最可靠的选择。 设置挂载选项 `noatime, nobarrier`.
Ext4是最可靠的选择。 设置挂载选项 `noatime`.
XFS也是合适的但它还没有经过ClickHouse的全面测试。
大多数其他文件系统也应该可以正常工作。 具有延迟分配的文件系统工作得更好。

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@ -6,20 +6,12 @@ toc_priority: 106
计算 `val` 最大值对应的 `arg` 值。 如果 `val` 最大值存在几个不同的 `arg` 值,输出遇到的第一个值。
这个函数的Tuple版本将返回 `val` 最大值对应的元组。本函数适合和 `SimpleAggregateFunction` 搭配使用。
**语法**
``` sql
argMax(arg, val)
```
``` sql
argMax(tuple(arg, val))
```
**参数**
- `arg` — Argument.
@ -31,12 +23,6 @@ argMax(tuple(arg, val))
类型: 匹配 `arg` 类型。
对于输入中的元组:
- 元组 `(arg, val)`, 其中 `val` 最大值,`arg` 是对应的值。
类型: [元组](../../../sql-reference/data-types/tuple.md)。
**示例**
输入表:
@ -52,13 +38,13 @@ argMax(tuple(arg, val))
查询:
``` sql
SELECT argMax(user, salary), argMax(tuple(user, salary), salary), argMax(tuple(user, salary)) FROM salary;
SELECT argMax(user, salary), argMax(tuple(user, salary), salary) FROM salary;
```
结果:
``` text
┌─argMax(user, salary)─┬─argMax(tuple(user, salary), salary)─┬─argMax(tuple(user, salary))─
│ director │ ('director',5000) │ ('director',5000) │
└──────────────────────┴─────────────────────────────────────┴─────────────────────────────
┌─argMax(user, salary)─┬─argMax(tuple(user, salary), salary)─┐
│ director │ ('director',5000) │
└──────────────────────┴─────────────────────────────────────┘
```

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@ -8,8 +8,6 @@ toc_priority: 105
计算 `val` 最小值对应的 `arg` 值。 如果 `val` 最小值存在几个不同的 `arg` 值,输出遇到的第一个(`arg`)值。
这个函数的Tuple版本将返回 `val` 最小值对应的tuple。本函数适合和`SimpleAggregateFunction`搭配使用。
**示例:**
输入表:
@ -25,13 +23,13 @@ toc_priority: 105
查询:
``` sql
SELECT argMin(user, salary), argMin(tuple(user, salary)) FROM salary;
SELECT argMin(user, salary), argMin(tuple(user, salary), salary) FROM salary;
```
结果:
``` text
┌─argMin(user, salary)─┬─argMin(tuple(user, salary))─┐
│ worker │ ('worker',1000) │
└──────────────────────┴─────────────────────────────┘
┌─argMin(user, salary)─┬─argMin(tuple(user, salary), salary)─┐
│ worker │ ('worker',1000)
└──────────────────────┴─────────────────────────────────────
```

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@ -86,7 +86,6 @@ void Client::processError(const String & query) const
{
if (server_exception)
{
bool print_stack_trace = config().getBool("stacktrace", false);
fmt::print(stderr, "Received exception from server (version {}):\n{}\n",
server_version,
getExceptionMessage(*server_exception, print_stack_trace, true));
@ -225,7 +224,7 @@ bool Client::executeMultiQuery(const String & all_queries_text)
{
// Surprisingly, this is a client error. A server error would
// have been reported w/o throwing (see onReceiveSeverException()).
client_exception = std::make_unique<Exception>(getCurrentExceptionMessage(true), getCurrentExceptionCode());
client_exception = std::make_unique<Exception>(getCurrentExceptionMessage(print_stack_trace), getCurrentExceptionCode());
have_error = true;
}
// Check whether the error (or its absence) matches the test hints
@ -489,8 +488,8 @@ try
}
catch (const Exception & e)
{
bool print_stack_trace = config().getBool("stacktrace", false) && e.code() != ErrorCodes::NETWORK_ERROR;
std::cerr << getExceptionMessage(e, print_stack_trace, true) << std::endl << std::endl;
bool need_print_stack_trace = config().getBool("stacktrace", false) && e.code() != ErrorCodes::NETWORK_ERROR;
std::cerr << getExceptionMessage(e, need_print_stack_trace, true) << std::endl << std::endl;
/// If exception code isn't zero, we should return non-zero return code anyway.
return e.code() ? e.code() : -1;
}
@ -813,7 +812,7 @@ bool Client::processWithFuzzing(const String & full_query)
// uniformity.
// Surprisingly, this is a client exception, because we get the
// server exception w/o throwing (see onReceiveException()).
client_exception = std::make_unique<Exception>(getCurrentExceptionMessage(true), getCurrentExceptionCode());
client_exception = std::make_unique<Exception>(getCurrentExceptionMessage(print_stack_trace), getCurrentExceptionCode());
have_error = true;
}
@ -1182,6 +1181,7 @@ void Client::processConfig()
if (!query_id.empty())
global_context->setCurrentQueryId(query_id);
}
print_stack_trace = config().getBool("stacktrace", false);
if (config().has("multiquery"))
is_multiquery = true;

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@ -5,6 +5,7 @@
#include <Common/DNSResolver.h>
#include <Interpreters/DNSCacheUpdater.h>
#include <Coordination/Defines.h>
#include <Common/Config/ConfigReloader.h>
#include <filesystem>
#include <IO/UseSSL.h>
#include <Core/ServerUUID.h>
@ -331,6 +332,8 @@ int Keeper::main(const std::vector<std::string> & /*args*/)
const Settings & settings = global_context->getSettingsRef();
std::string include_from_path = config().getString("include_from", "/etc/metrika.xml");
GlobalThreadPool::initialize(config().getUInt("max_thread_pool_size", 100));
static ServerErrorHandler error_handler;
@ -402,8 +405,27 @@ int Keeper::main(const std::vector<std::string> & /*args*/)
for (auto & server : *servers)
server.start();
zkutil::EventPtr unused_event = std::make_shared<Poco::Event>();
zkutil::ZooKeeperNodeCache unused_cache([] { return nullptr; });
/// ConfigReloader have to strict parameters which are redundant in our case
auto main_config_reloader = std::make_unique<ConfigReloader>(
config_path,
include_from_path,
config().getString("path", ""),
std::move(unused_cache),
unused_event,
[&](ConfigurationPtr config, bool /* initial_loading */)
{
if (config->has("keeper_server"))
global_context->updateKeeperConfiguration(*config);
},
/* already_loaded = */ false); /// Reload it right now (initial loading)
SCOPE_EXIT({
LOG_INFO(log, "Shutting down.");
/// Stop reloading of the main config. This must be done before `global_context->shutdown()` because
/// otherwise the reloading may pass a changed config to some destroyed parts of ContextSharedPart.
main_config_reloader.reset();
global_context->shutdown();
@ -450,6 +472,7 @@ int Keeper::main(const std::vector<std::string> & /*args*/)
buildLoggers(config(), logger());
main_config_reloader->start();
LOG_INFO(log, "Ready for connections.");

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@ -18,7 +18,9 @@
#include <Common/Macros.h>
#include <Common/Config/ConfigProcessor.h>
#include <Common/ThreadStatus.h>
#include <Common/TLDListsHolder.h>
#include <Common/quoteString.h>
#include <Common/randomSeed.h>
#include <loggers/Loggers.h>
#include <IO/ReadBufferFromFile.h>
#include <IO/ReadBufferFromString.h>
@ -35,7 +37,6 @@
#include <Formats/registerFormats.h>
#include <boost/program_options/options_description.hpp>
#include <base/argsToConfig.h>
#include <Common/randomSeed.h>
#include <filesystem>
namespace fs = std::filesystem;
@ -62,7 +63,6 @@ void LocalServer::processError(const String &) const
String message;
if (server_exception)
{
bool print_stack_trace = config().getBool("stacktrace", false);
message = getExceptionMessage(*server_exception, print_stack_trace, true);
}
else if (client_exception)
@ -131,9 +131,12 @@ bool LocalServer::executeMultiQuery(const String & all_queries_text)
}
catch (...)
{
if (!is_interactive && !ignore_error)
throw;
// Surprisingly, this is a client error. A server error would
// have been reported w/o throwing (see onReceiveSeverException()).
client_exception = std::make_unique<Exception>(getCurrentExceptionMessage(true), getCurrentExceptionCode());
client_exception = std::make_unique<Exception>(getCurrentExceptionMessage(print_stack_trace), getCurrentExceptionCode());
have_error = true;
}
@ -177,7 +180,6 @@ void LocalServer::initialize(Poco::Util::Application & self)
ConfigProcessor config_processor(config_path, false, true);
config_processor.setConfigPath(fs::path(config_path).parent_path());
auto loaded_config = config_processor.loadConfig();
config_processor.savePreprocessedConfig(loaded_config, loaded_config.configuration->getString("path", "."));
config().add(loaded_config.configuration.duplicate(), PRIO_DEFAULT, false);
}
@ -282,28 +284,40 @@ void LocalServer::tryInitPath()
global_context->setFlagsPath(path + "flags");
global_context->setUserFilesPath(""); // user's files are everywhere
/// top_level_domains_lists
const std::string & top_level_domains_path = config().getString("top_level_domains_path", path + "top_level_domains/");
if (!top_level_domains_path.empty())
TLDListsHolder::getInstance().parseConfig(fs::path(top_level_domains_path) / "", config());
}
void LocalServer::cleanup()
{
connection.reset();
if (global_context)
try
{
global_context->shutdown();
global_context.reset();
connection.reset();
if (global_context)
{
global_context->shutdown();
global_context.reset();
}
status.reset();
// Delete the temporary directory if needed.
if (temporary_directory_to_delete)
{
const auto dir = *temporary_directory_to_delete;
temporary_directory_to_delete.reset();
LOG_DEBUG(&logger(), "Removing temporary directory: {}", dir.string());
remove_all(dir);
}
}
status.reset();
// Delete the temporary directory if needed.
if (temporary_directory_to_delete)
catch (...)
{
const auto dir = *temporary_directory_to_delete;
temporary_directory_to_delete.reset();
LOG_DEBUG(&logger(), "Removing temporary directory: {}", dir.string());
remove_all(dir);
tryLogCurrentException(__PRETTY_FUNCTION__);
}
}
@ -371,7 +385,6 @@ void LocalServer::setupUsers()
const auto users_config_path = config().getString("users_config", config().getString("config-file", "config.xml"));
ConfigProcessor config_processor(users_config_path);
const auto loaded_config = config_processor.loadConfig();
config_processor.savePreprocessedConfig(loaded_config, config().getString("path", DBMS_DEFAULT_PATH));
users_config = loaded_config.configuration;
}
else
@ -446,23 +459,20 @@ try
cleanup();
return Application::EXIT_OK;
}
catch (const DB::Exception & e)
{
cleanup();
bool need_print_stack_trace = config().getBool("stacktrace", false);
std::cerr << getExceptionMessage(e, need_print_stack_trace, true) << std::endl;
return e.code() ? e.code() : -1;
}
catch (...)
{
try
{
cleanup();
}
catch (...)
{
tryLogCurrentException(__PRETTY_FUNCTION__);
}
cleanup();
if (!ignore_error)
std::cerr << getCurrentExceptionMessage(config().hasOption("stacktrace")) << '\n';
auto code = getCurrentExceptionCode();
/// If exception code isn't zero, we should return non-zero return code anyway.
return code ? code : -1;
std::cerr << getCurrentExceptionMessage(false) << std::endl;
return getCurrentExceptionCode();
}
@ -485,6 +495,7 @@ void LocalServer::processConfig()
ignore_error = config().getBool("ignore-error", false);
is_multiquery = true;
}
print_stack_trace = config().getBool("stacktrace", false);
shared_context = Context::createShared();
global_context = Context::createGlobal(shared_context.get());
@ -666,6 +677,7 @@ void LocalServer::addOptions(OptionsDescription & options_description)
("no-system-tables", "do not attach system tables (better startup time)")
("path", po::value<std::string>(), "Storage path")
("top_level_domains_path", po::value<std::string>(), "Path to lists with custom TLDs")
;
}

View File

@ -863,6 +863,9 @@ if (ThreadFuzzer::instance().isEffective())
if (config->has("max_concurrent_queries"))
global_context->getProcessList().setMaxSize(config->getInt("max_concurrent_queries", 0));
if (config->has("keeper_server"))
global_context->updateKeeperConfiguration(*config);
if (!initial_loading)
{
/// We do not load ZooKeeper configuration on the first config loading
@ -957,9 +960,14 @@ if (ThreadFuzzer::instance().isEffective())
global_context->setMMappedFileCache(mmap_cache_size);
#if USE_EMBEDDED_COMPILER
/// 128 MB
constexpr size_t compiled_expression_cache_size_default = 1024 * 1024 * 128;
size_t compiled_expression_cache_size = config().getUInt64("compiled_expression_cache_size", compiled_expression_cache_size_default);
CompiledExpressionCacheFactory::instance().init(compiled_expression_cache_size);
constexpr size_t compiled_expression_cache_elements_size_default = 10000;
size_t compiled_expression_cache_elements_size = config().getUInt64("compiled_expression_cache_elements_size", compiled_expression_cache_elements_size_default);
CompiledExpressionCacheFactory::instance().init(compiled_expression_cache_size, compiled_expression_cache_elements_size);
#endif
/// Set path for format schema files

View File

@ -351,9 +351,12 @@
-->
<mmap_cache_size>1000</mmap_cache_size>
<!-- Cache size for compiled expressions.-->
<!-- Cache size in bytes for compiled expressions.-->
<compiled_expression_cache_size>134217728</compiled_expression_cache_size>
<!-- Cache size in elements for compiled expressions.-->
<compiled_expression_cache_elements_size>10000</compiled_expression_cache_elements_size>
<!-- Path to data directory, with trailing slash. -->
<path>/var/lib/clickhouse/</path>

View File

@ -279,9 +279,12 @@ mark_cache_size: 5368709120
# also it can be dropped manually by the SYSTEM DROP MMAP CACHE query.
mmap_cache_size: 1000
# Cache size for compiled expressions.
# Cache size in bytes for compiled expressions.
compiled_expression_cache_size: 134217728
# Cache size in elements for compiled expressions.
compiled_expression_cache_elements_size: 10000
# Path to data directory, with trailing slash.
path: /var/lib/clickhouse/

View File

@ -338,7 +338,7 @@
<body>
<div id="inputs">
<input class="monospace shadow" id="url" type="text" value="http://localhost:8123/" /><input class="monospace shadow" id="user" type="text" value="default" /><input class="monospace shadow" id="password" type="password" />
<input class="monospace shadow" id="url" type="text" value="http://localhost:8123/" placeholder="url" /><input class="monospace shadow" id="user" type="text" value="default" placeholder="user" /><input class="monospace shadow" id="password" type="password" placeholder="password" />
</div>
<div>
<textarea autofocus spellcheck="false" class="monospace shadow" id="query"></textarea>
@ -549,13 +549,38 @@
document.getElementById('logo-container').style.display = 'block';
}
function formatReadable(number = 0, decimals = 2, units = []) {
const k = 1000;
const i = number ? Math.floor(Math.log(number) / Math.log(k)) : 0;
const unit = units[i];
const dm = unit ? decimals : 0;
return Number(number / Math.pow(k, i)).toFixed(dm) + unit;
}
function formatReadableBytes(bytes) {
const units = [' B', ' KB', ' MB', ' GB', ' TB', ' PB', ' EB', ' ZB', ' YB'];
return formatReadable(bytes, 2, units);
}
function formatReadableRows(rows) {
const units = ['', ' thousand', ' million', ' billion', ' trillion', ' quadrillion'];
return formatReadable(rows, 2, units);
}
function renderResult(response)
{
clear();
let stats = document.getElementById('stats');
stats.innerText = 'Elapsed: ' + response.statistics.elapsed.toFixed(3) + " sec, read " + response.statistics.rows_read + " rows.";
const seconds = response.statistics.elapsed.toFixed(3);
const rows = response.statistics.rows_read;
const bytes = response.statistics.bytes_read;
const formatted_bytes = formatReadableBytes(bytes);
const formatted_rows = formatReadableRows(rows);
stats.innerText = `Elapsed: ${seconds} sec, read ${formatted_rows} rows, ${formatted_bytes}.`;
/// We can also render graphs if user performed EXPLAIN PIPELINE graph=1.
if (response.data.length > 3 && response.data[0][0] === "digraph" && document.getElementById('query').value.match(/^\s*EXPLAIN/i)) {

View File

@ -110,7 +110,7 @@ enum class AccessType
(anyone can kill his own queries) */\
\
M(MOVE_PARTITION_BETWEEN_SHARDS, "", GLOBAL, ALL) /* required to be able to move a part/partition to a table
identified by it's ZooKeeper path */\
identified by its ZooKeeper path */\
\
M(CREATE_USER, "", GLOBAL, ACCESS_MANAGEMENT) \
M(ALTER_USER, "", GLOBAL, ACCESS_MANAGEMENT) \

View File

@ -41,7 +41,7 @@ std::unique_ptr<ReadBuffer> BackupEntryFromImmutableFile::getReadBuffer() const
if (disk)
return disk->readFile(file_path);
else
return createReadBufferFromFileBase(file_path, {}, 0);
return createReadBufferFromFileBase(file_path, /* settings= */ {});
}
}

View File

@ -10,7 +10,7 @@ namespace
{
String readFile(const String & file_path)
{
auto buf = createReadBufferFromFileBase(file_path, {}, 0);
auto buf = createReadBufferFromFileBase(file_path, /* settings= */ {});
String s;
readStringUntilEOF(s, *buf);
return s;

View File

@ -109,6 +109,10 @@ if (USE_HDFS)
add_headers_and_sources(dbms Disks/HDFS)
endif()
if(USE_FILELOG)
add_headers_and_sources(dbms Storages/FileLog)
endif()
list (APPEND clickhouse_common_io_sources ${CONFIG_BUILD})
list (APPEND clickhouse_common_io_headers ${CONFIG_VERSION} ${CONFIG_COMMON})
@ -285,6 +289,13 @@ target_link_libraries (clickhouse_common_io
dragonbox_to_chars
)
# Use X86 AVX2/AVX512 instructions to accelerate filter operations
set_source_files_properties(
Columns/ColumnFixedString.cpp
Columns/ColumnsCommon.cpp
Columns/ColumnVector.cpp
PROPERTIES COMPILE_FLAGS "${X86_INTRINSICS_FLAGS}")
if(RE2_LIBRARY)
target_link_libraries(clickhouse_common_io PUBLIC ${RE2_LIBRARY})
endif()

View File

@ -1370,9 +1370,7 @@ void ClientBase::runInteractive()
catch (const Exception & e)
{
/// We don't need to handle the test hints in the interactive mode.
bool print_stack_trace = config().getBool("stacktrace", false);
std::cerr << "Exception on client:" << std::endl << getExceptionMessage(e, print_stack_trace, true) << std::endl << std::endl;
client_exception = std::make_unique<Exception>(e);
}

View File

@ -202,6 +202,7 @@ protected:
bool written_first_block = false;
size_t processed_rows = 0; /// How many rows have been read or written.
bool print_stack_trace = false;
/// The last exception that was received from the server. Is used for the
/// return code in batch mode.
std::unique_ptr<Exception> server_exception;

View File

@ -236,12 +236,12 @@ void HedgedConnections::sendCancel()
if (!sent_query || cancelled)
throw Exception("Cannot cancel. Either no query sent or already cancelled.", ErrorCodes::LOGICAL_ERROR);
cancelled = true;
for (auto & offset_status : offset_states)
for (auto & replica : offset_status.replicas)
if (replica.connection)
replica.connection->sendCancel();
cancelled = true;
}
Packet HedgedConnections::drain()

View File

@ -285,13 +285,6 @@ bool LocalConnection::poll(size_t)
return true;
}
if (send_progress && !state->sent_progress)
{
state->sent_progress = true;
next_packet_type = Protocol::Server::Progress;
return true;
}
if (state->block && state->block.value())
{
next_packet_type = Protocol::Server::Data;

View File

@ -237,6 +237,26 @@ ColumnPtr ColumnDecimal<T>::filter(const IColumn::Filter & filt, ssize_t result_
const UInt8 * filt_end = filt_pos + size;
const T * data_pos = data.data();
#ifdef __SSE2__
static constexpr size_t SIMD_BYTES = 16;
const __m128i zero16 = _mm_setzero_si128();
const UInt8 * filt_end_sse = filt_pos + size / SIMD_BYTES * SIMD_BYTES;
while (filt_pos < filt_end_sse)
{
UInt16 mask = _mm_movemask_epi8(_mm_cmpeq_epi8(_mm_loadu_si128(reinterpret_cast<const __m128i *>(filt_pos)), zero16));
mask = ~mask;
while (mask)
{
size_t index = __builtin_ctz(mask);
res_data.push_back(*(data_pos + index));
mask = mask & (mask - 1);
}
filt_pos += SIMD_BYTES;
data_pos += SIMD_BYTES;
}
#endif
while (filt_pos < filt_end)
{
if (*filt_pos)

View File

@ -231,12 +231,79 @@ ColumnPtr ColumnFixedString::filter(const IColumn::Filter & filt, ssize_t result
const UInt8 * filt_end = filt_pos + col_size;
const UInt8 * data_pos = chars.data();
#ifdef __SSE2__
/** A slightly more optimized version.
* Based on the assumption that often pieces of consecutive values
* completely pass or do not pass the filter.
* Therefore, we will optimistically check the parts of `SIMD_BYTES` values.
*/
#if defined(__AVX512F__) && defined(__AVX512BW__)
static constexpr size_t SIMD_BYTES = 64;
const __m512i zero64 = _mm512_setzero_epi32();
const UInt8 * filt_end_avx512 = filt_pos + col_size / SIMD_BYTES * SIMD_BYTES;
const size_t chars_per_simd_elements = SIMD_BYTES * n;
while (filt_pos < filt_end_avx512)
{
uint64_t mask = _mm512_cmp_epi8_mask(_mm512_loadu_si512(reinterpret_cast<const __m512i *>(filt_pos)), zero64, _MM_CMPINT_GT);
if (0xFFFFFFFFFFFFFFFF == mask)
{
res->chars.insert(data_pos, data_pos + chars_per_simd_elements);
}
else
{
size_t res_chars_size = res->chars.size();
while (mask)
{
size_t index = __builtin_ctzll(mask);
res->chars.resize(res_chars_size + n);
memcpySmallAllowReadWriteOverflow15(&res->chars[res_chars_size], data_pos + index * n, n);
res_chars_size += n;
#ifdef __BMI__
mask = _blsr_u64(mask);
#else
mask = mask & (mask-1);
#endif
}
}
data_pos += chars_per_simd_elements;
filt_pos += SIMD_BYTES;
}
#elif defined(__AVX__) && defined(__AVX2__)
static constexpr size_t SIMD_BYTES = 32;
const __m256i zero32 = _mm256_setzero_si256();
const UInt8 * filt_end_avx2 = filt_pos + col_size / SIMD_BYTES * SIMD_BYTES;
const size_t chars_per_simd_elements = SIMD_BYTES * n;
while (filt_pos < filt_end_avx2)
{
uint32_t mask = _mm256_movemask_epi8(_mm256_cmpgt_epi8(_mm256_loadu_si256(reinterpret_cast<const __m256i *>(filt_pos)), zero32));
if (0xFFFFFFFF == mask)
{
res->chars.insert(data_pos, data_pos + chars_per_simd_elements);
}
else
{
size_t res_chars_size = res->chars.size();
while (mask)
{
size_t index = __builtin_ctz(mask);
res->chars.resize(res_chars_size + n);
memcpySmallAllowReadWriteOverflow15(&res->chars[res_chars_size], data_pos + index * n, n);
res_chars_size += n;
#ifdef __BMI__
mask = _blsr_u32(mask);
#else
mask = mask & (mask-1);
#endif
}
}
data_pos += chars_per_simd_elements;
filt_pos += SIMD_BYTES;
}
#elif defined(__SSE2__)
static constexpr size_t SIMD_BYTES = 16;
const __m128i zero16 = _mm_setzero_si128();
@ -267,6 +334,7 @@ ColumnPtr ColumnFixedString::filter(const IColumn::Filter & filt, ssize_t result
data_pos += chars_per_simd_elements;
filt_pos += SIMD_BYTES;
}
#endif
size_t res_chars_size = res->chars.size();

View File

@ -310,14 +310,74 @@ ColumnPtr ColumnVector<T>::filter(const IColumn::Filter & filt, ssize_t result_s
const UInt8 * filt_pos = filt.data();
const UInt8 * filt_end = filt_pos + size;
const T * data_pos = data.data();
#ifdef __SSE2__
/** A slightly more optimized version.
* Based on the assumption that often pieces of consecutive values
* completely pass or do not pass the filter.
* Therefore, we will optimistically check the parts of `SIMD_BYTES` values.
*/
#if defined(__AVX512F__) && defined(__AVX512BW__)
static constexpr size_t SIMD_BYTES = 64;
const __m512i zero64 = _mm512_setzero_epi32();
const UInt8 * filt_end_avx512 = filt_pos + size / SIMD_BYTES * SIMD_BYTES;
while (filt_pos < filt_end_avx512)
{
UInt64 mask = _mm512_cmp_epi8_mask(_mm512_loadu_si512(reinterpret_cast<const __m512i *>(filt_pos)), zero64, _MM_CMPINT_GT);
if (0xFFFFFFFFFFFFFFFF == mask)
{
res_data.insert(data_pos, data_pos + SIMD_BYTES);
}
else
{
while (mask)
{
size_t index = __builtin_ctzll(mask);
res_data.push_back(data_pos[index]);
#ifdef __BMI__
mask = _blsr_u64(mask);
#else
mask = mask & (mask-1);
#endif
}
}
filt_pos += SIMD_BYTES;
data_pos += SIMD_BYTES;
}
#elif defined(__AVX__) && defined(__AVX2__)
static constexpr size_t SIMD_BYTES = 32;
const __m256i zero32 = _mm256_setzero_si256();
const UInt8 * filt_end_avx2 = filt_pos + size / SIMD_BYTES * SIMD_BYTES;
while (filt_pos < filt_end_avx2)
{
UInt32 mask = _mm256_movemask_epi8(_mm256_cmpgt_epi8(_mm256_loadu_si256(reinterpret_cast<const __m256i *>(filt_pos)), zero32));
if (0xFFFFFFFF == mask)
{
res_data.insert(data_pos, data_pos + SIMD_BYTES);
}
else
{
while (mask)
{
size_t index = __builtin_ctz(mask);
res_data.push_back(data_pos[index]);
#ifdef __BMI__
mask = _blsr_u32(mask);
#else
mask = mask & (mask-1);
#endif
}
}
filt_pos += SIMD_BYTES;
data_pos += SIMD_BYTES;
}
#elif defined(__SSE2__)
static constexpr size_t SIMD_BYTES = 16;
const __m128i zero16 = _mm_setzero_si128();
const UInt8 * filt_end_sse = filt_pos + size / SIMD_BYTES * SIMD_BYTES;
@ -344,6 +404,7 @@ ColumnPtr ColumnVector<T>::filter(const IColumn::Filter & filt, ssize_t result_s
filt_pos += SIMD_BYTES;
data_pos += SIMD_BYTES;
}
#endif
while (filt_pos < filt_end)

View File

@ -229,7 +229,89 @@ namespace
memcpy(&res_elems[elems_size_old], &src_elems[arr_offset], arr_size * sizeof(T));
};
#ifdef __SSE2__
#if defined(__AVX512F__) && defined(__AVX512BW__)
const __m512i zero_vec = _mm512_setzero_epi32();
static constexpr size_t SIMD_BYTES = 64;
const auto * filt_end_aligned = filt_pos + size / SIMD_BYTES * SIMD_BYTES;
while (filt_pos < filt_end_aligned)
{
uint64_t mask = _mm512_cmp_epi8_mask(_mm512_loadu_si512(reinterpret_cast<const __m512i *>(filt_pos)), zero_vec, _MM_CMPINT_GT);
if (mask == 0xffffffffffffffff)
{
/// SIMD_BYTES consecutive rows pass the filter
const auto first = offsets_pos == offsets_begin;
const auto chunk_offset = first ? 0 : offsets_pos[-1];
const auto chunk_size = offsets_pos[SIMD_BYTES - 1] - chunk_offset;
result_offsets_builder.template insertChunk<SIMD_BYTES>(offsets_pos, first, chunk_offset, chunk_size);
/// copy elements for SIMD_BYTES arrays at once
const auto elems_size_old = res_elems.size();
res_elems.resize(elems_size_old + chunk_size);
memcpy(&res_elems[elems_size_old], &src_elems[chunk_offset], chunk_size * sizeof(T));
}
else
{
while (mask)
{
size_t index = __builtin_ctzll(mask);
copy_array(offsets_pos + index);
#ifdef __BMI__
mask = _blsr_u64(mask);
#else
mask = mask & (mask-1);
#endif
}
}
filt_pos += SIMD_BYTES;
offsets_pos += SIMD_BYTES;
}
#elif defined(__AVX__) && defined(__AVX2__)
const __m256i zero_vec = _mm256_setzero_si256();
static constexpr size_t SIMD_BYTES = 32;
const auto * filt_end_aligned = filt_pos + size / SIMD_BYTES * SIMD_BYTES;
while (filt_pos < filt_end_aligned)
{
uint32_t mask = _mm256_movemask_epi8(_mm256_cmpgt_epi8(_mm256_loadu_si256(reinterpret_cast<const __m256i *>(filt_pos)), zero_vec));
if (mask == 0xffffffff)
{
/// SIMD_BYTES consecutive rows pass the filter
const auto first = offsets_pos == offsets_begin;
const auto chunk_offset = first ? 0 : offsets_pos[-1];
const auto chunk_size = offsets_pos[SIMD_BYTES - 1] - chunk_offset;
result_offsets_builder.template insertChunk<SIMD_BYTES>(offsets_pos, first, chunk_offset, chunk_size);
/// copy elements for SIMD_BYTES arrays at once
const auto elems_size_old = res_elems.size();
res_elems.resize(elems_size_old + chunk_size);
memcpy(&res_elems[elems_size_old], &src_elems[chunk_offset], chunk_size * sizeof(T));
}
else
{
while (mask)
{
size_t index = __builtin_ctz(mask);
copy_array(offsets_pos + index);
#ifdef __BMI__
mask = _blsr_u32(mask);
#else
mask = mask & (mask-1);
#endif
}
}
filt_pos += SIMD_BYTES;
offsets_pos += SIMD_BYTES;
}
#elif defined(__SSE2__)
const __m128i zero_vec = _mm_setzero_si128();
static constexpr size_t SIMD_BYTES = 16;
const auto * filt_end_aligned = filt_pos + size / SIMD_BYTES * SIMD_BYTES;

View File

@ -591,6 +591,8 @@
M(621, CANNOT_NORMALIZE_STRING) \
M(622, CANNOT_PARSE_CAPN_PROTO_SCHEMA) \
M(623, CAPN_PROTO_BAD_CAST) \
M(624, BAD_FILE_TYPE) \
M(625, IO_SETUP_ERROR) \
\
M(999, KEEPER_EXCEPTION) \
M(1000, POCO_EXCEPTION) \

View File

@ -36,12 +36,13 @@ public:
using Mapped = TMapped;
using MappedPtr = std::shared_ptr<Mapped>;
private:
using Clock = std::chrono::steady_clock;
public:
LRUCache(size_t max_size_)
: max_size(std::max(static_cast<size_t>(1), max_size_)) {}
/** Initialize LRUCache with max_size and max_elements_size.
* max_elements_size == 0 means no elements size restrictions.
*/
LRUCache(size_t max_size_, size_t max_elements_size_ = 0)
: max_size(std::max(static_cast<size_t>(1), max_size_))
, max_elements_size(max_elements_size_)
{}
MappedPtr get(const Key & key)
{
@ -252,6 +253,7 @@ private:
/// Total weight of values.
size_t current_size = 0;
const size_t max_size;
const size_t max_elements_size;
std::atomic<size_t> hits {0};
std::atomic<size_t> misses {0};
@ -311,7 +313,8 @@ private:
{
size_t current_weight_lost = 0;
size_t queue_size = cells.size();
while ((current_size > max_size) && (queue_size > 1))
while ((current_size > max_size || (max_elements_size != 0 && queue_size > max_elements_size)) && (queue_size > 1))
{
const Key & key = queue.front();

View File

@ -227,7 +227,8 @@
M(CreatedHTTPConnections, "Total amount of created HTTP connections (counter increase every time connection is created).") \
\
M(CannotWriteToWriteBufferDiscard, "Number of stack traces dropped by query profiler or signal handler because pipe is full or cannot write to pipe.") \
M(QueryProfilerSignalOverruns, "Number of times we drop processing of a signal due to overrun plus the number of signals that OS has not delivered due to overrun.") \
M(QueryProfilerSignalOverruns, "Number of times we drop processing of a query profiler signal due to overrun plus the number of signals that OS has not delivered due to overrun.") \
M(QueryProfilerRuns, "Number of times QueryProfiler had been run.") \
\
M(CreatedLogEntryForMerge, "Successfully created log entry to merge parts in ReplicatedMergeTree.") \
M(NotCreatedLogEntryForMerge, "Log entry to merge parts in ReplicatedMergeTree is not created due to concurrent log update by another replica.") \

View File

@ -14,17 +14,19 @@
namespace
{
constexpr UInt64 ZERO = 0;
constexpr UInt64 ALL_THREADS = 0;
UInt64 calculateNewCoresNumber(DB::ThreadIdToTimeMap const & prev, DB::ThreadIdToTimeMap const& next)
{
if (next.find(ZERO) == next.end())
return ZERO;
auto accumulated = std::accumulate(next.cbegin(), next.cend(), ZERO,
[&prev](UInt64 acc, auto const & elem)
if (next.find(ALL_THREADS) == next.end())
return 0;
auto accumulated = std::accumulate(next.cbegin(), next.cend(), 0,
[&prev](UInt64 acc, const auto & elem)
{
if (elem.first == ZERO)
if (elem.first == ALL_THREADS)
return acc;
auto thread_time = elem.second.time();
auto it = prev.find(elem.first);
if (it != prev.end())
@ -32,9 +34,9 @@ namespace
return acc + thread_time;
});
auto elapsed = next.at(ZERO).time() - (prev.contains(ZERO) ? prev.at(ZERO).time() : ZERO);
if (elapsed == ZERO)
return ZERO;
auto elapsed = next.at(ALL_THREADS).time() - (prev.contains(ALL_THREADS) ? prev.at(ALL_THREADS).time() : 0);
if (elapsed == 0)
return 0;
return (accumulated + elapsed - 1) / elapsed;
}
}
@ -109,7 +111,7 @@ size_t ProgressIndication::getUsedThreadsCount() const
UInt64 ProgressIndication::getApproximateCoresNumber() const
{
return std::accumulate(host_active_cores.cbegin(), host_active_cores.cend(), ZERO,
return std::accumulate(host_active_cores.cbegin(), host_active_cores.cend(), 0,
[](UInt64 acc, auto const & elem)
{
return acc + elem.second;
@ -121,11 +123,12 @@ ProgressIndication::MemoryUsage ProgressIndication::getMemoryUsage() const
return std::accumulate(thread_data.cbegin(), thread_data.cend(), MemoryUsage{},
[](MemoryUsage const & acc, auto const & host_data)
{
auto host_usage = std::accumulate(host_data.second.cbegin(), host_data.second.cend(), ZERO,
[](UInt64 memory, auto const & data)
{
return memory + data.second.memory_usage;
});
UInt64 host_usage = 0;
// In ProfileEvents packets thread id 0 specifies common profiling information
// for all threads executing current query on specific host. So instead of summing per thread
// memory consumption it's enough to look for data with thread id 0.
if (auto it = host_data.second.find(ALL_THREADS); it != host_data.second.end())
host_usage = it->second.memory_usage;
return MemoryUsage{.total = acc.total + host_usage, .max = std::max(acc.max, host_usage)};
});
}

View File

@ -15,6 +15,7 @@
namespace ProfileEvents
{
extern const Event QueryProfilerSignalOverruns;
extern const Event QueryProfilerRuns;
}
namespace DB
@ -60,6 +61,7 @@ namespace
const StackTrace stack_trace(signal_context);
TraceCollector::collect(trace_type, stack_trace, 0);
ProfileEvents::increment(ProfileEvents::QueryProfilerRuns);
errno = saved_errno;
}

View File

@ -116,9 +116,9 @@ public:
/// lower and uppercase variants of the first octet of the first character in `needle`
size_t length_l = UTF8::convertCodePointToUTF8(first_l_u32, l_seq, sizeof(l_seq));
size_t length_r = UTF8::convertCodePointToUTF8(first_u_u32, u_seq, sizeof(u_seq));
size_t length_u = UTF8::convertCodePointToUTF8(first_u_u32, u_seq, sizeof(u_seq));
if (length_l != length_r)
if (length_l != length_u)
throw Exception{"UTF8 sequences with different lowercase and uppercase lengths are not supported", ErrorCodes::UNSUPPORTED_PARAMETER};
}
@ -183,6 +183,31 @@ public:
#endif
}
template <typename CharT, typename = std::enable_if_t<sizeof(CharT) == 1>>
ALWAYS_INLINE bool compareTrivial(const CharT * haystack_pos, const CharT * const haystack_end, const uint8_t * needle_pos) const
{
while (haystack_pos < haystack_end && needle_pos < needle_end)
{
auto haystack_code_point = UTF8::convertUTF8ToCodePoint(haystack_pos, haystack_end - haystack_pos);
auto needle_code_point = UTF8::convertUTF8ToCodePoint(needle_pos, needle_end - needle_pos);
/// Invalid UTF-8, should not compare equals
if (!haystack_code_point || !needle_code_point)
break;
/// Not equals case insensitive.
if (Poco::Unicode::toLower(*haystack_code_point) != Poco::Unicode::toLower(*needle_code_point))
break;
/// @note assuming sequences for lowercase and uppercase have exact same length (that is not always true)
const auto len = UTF8::seqLength(*haystack_pos);
haystack_pos += len;
needle_pos += len;
}
return needle_pos == needle_end;
}
template <typename CharT, typename = std::enable_if_t<sizeof(CharT) == 1>>
ALWAYS_INLINE bool compare(const CharT * /*haystack*/, const CharT * haystack_end, const CharT * pos) const
{
@ -200,34 +225,15 @@ public:
{
if (mask == cachemask)
{
pos += cache_valid_len;
auto needle_pos = needle + cache_valid_len;
while (needle_pos < needle_end)
{
auto haystack_code_point = UTF8::convertUTF8ToCodePoint(pos, haystack_end - pos);
auto needle_code_point = UTF8::convertUTF8ToCodePoint(needle_pos, needle_end - needle_pos);
/// Invalid UTF-8, should not compare equals
if (!haystack_code_point || !needle_code_point)
break;
/// Not equals case insensitive.
if (Poco::Unicode::toLower(*haystack_code_point) != Poco::Unicode::toLower(*needle_code_point))
break;
/// @note assuming sequences for lowercase and uppercase have exact same length (that is not always true)
const auto len = UTF8::seqLength(*pos);
pos += len;
needle_pos += len;
}
if (needle_pos == needle_end)
if (compareTrivial(pos, haystack_end, needle))
return true;
}
}
else if ((mask & cachemask) == cachemask)
return true;
{
if (compareTrivial(pos, haystack_end, needle))
return true;
}
return false;
}
@ -238,25 +244,7 @@ public:
pos += first_needle_symbol_is_ascii;
auto needle_pos = needle + first_needle_symbol_is_ascii;
while (needle_pos < needle_end)
{
auto haystack_code_point = UTF8::convertUTF8ToCodePoint(pos, haystack_end - pos);
auto needle_code_point = UTF8::convertUTF8ToCodePoint(needle_pos, needle_end - needle_pos);
/// Invalid UTF-8, should not compare equals
if (!haystack_code_point || !needle_code_point)
break;
/// Not equals case insensitive.
if (Poco::Unicode::toLower(*haystack_code_point) != Poco::Unicode::toLower(*needle_code_point))
break;
const auto len = UTF8::seqLength(*pos);
pos += len;
needle_pos += len;
}
if (needle_pos == needle_end)
if (compareTrivial(pos, haystack_end, needle_pos))
return true;
}
@ -299,40 +287,21 @@ public:
const auto v_against_l_offset = _mm_cmpeq_epi8(v_haystack_offset, cachel);
const auto v_against_u_offset = _mm_cmpeq_epi8(v_haystack_offset, cacheu);
const auto v_against_l_or_u_offset = _mm_or_si128(v_against_l_offset, v_against_u_offset);
const auto mask_offset = _mm_movemask_epi8(v_against_l_or_u_offset);
const auto mask_offset_both = _mm_movemask_epi8(v_against_l_or_u_offset);
if (0xffff == cachemask)
{
if (mask_offset == cachemask)
if (mask_offset_both == cachemask)
{
auto haystack_pos = haystack + cache_valid_len;
auto needle_pos = needle + cache_valid_len;
while (haystack_pos < haystack_end && needle_pos < needle_end)
{
auto haystack_code_point = UTF8::convertUTF8ToCodePoint(haystack_pos, haystack_end - haystack_pos);
auto needle_code_point = UTF8::convertUTF8ToCodePoint(needle_pos, needle_end - needle_pos);
/// Invalid UTF-8, should not compare equals
if (!haystack_code_point || !needle_code_point)
break;
/// Not equals case insensitive.
if (Poco::Unicode::toLower(*haystack_code_point) != Poco::Unicode::toLower(*needle_code_point))
break;
/// @note assuming sequences for lowercase and uppercase have exact same length (that is not always true)
const auto len = UTF8::seqLength(*haystack_pos);
haystack_pos += len;
needle_pos += len;
}
if (needle_pos == needle_end)
if (compareTrivial(haystack, haystack_end, needle))
return haystack;
}
}
else if ((mask_offset & cachemask) == cachemask)
return haystack;
else if ((mask_offset_both & cachemask) == cachemask)
{
if (compareTrivial(haystack, haystack_end, needle))
return haystack;
}
/// first octet was ok, but not the first 16, move to start of next sequence and reapply
haystack += UTF8::seqLength(*haystack);
@ -349,25 +318,7 @@ public:
auto haystack_pos = haystack + first_needle_symbol_is_ascii;
auto needle_pos = needle + first_needle_symbol_is_ascii;
while (haystack_pos < haystack_end && needle_pos < needle_end)
{
auto haystack_code_point = UTF8::convertUTF8ToCodePoint(haystack_pos, haystack_end - haystack_pos);
auto needle_code_point = UTF8::convertUTF8ToCodePoint(needle_pos, needle_end - needle_pos);
/// Invalid UTF-8, should not compare equals
if (!haystack_code_point || !needle_code_point)
break;
/// Not equals case insensitive.
if (Poco::Unicode::toLower(*haystack_code_point) != Poco::Unicode::toLower(*needle_code_point))
break;
const auto len = UTF8::seqLength(*haystack_pos);
haystack_pos += len;
needle_pos += len;
}
if (needle_pos == needle_end)
if (compareTrivial(haystack_pos, haystack_end, needle_pos))
return haystack;
}

View File

@ -730,7 +730,10 @@ bool ZooKeeper::waitForDisappear(const std::string & path, const WaitCondition &
}
};
while (!condition || !condition())
/// do-while control structure to allow using this function in non-blocking
/// fashion with a wait condition which returns false by the time this
/// method is called.
do
{
/// Use getData insteand of exists to avoid watch leak.
impl->get(path, callback, watch);
@ -746,7 +749,8 @@ bool ZooKeeper::waitForDisappear(const std::string & path, const WaitCondition &
if (state->event_type == Coordination::DELETED)
return true;
}
} while (!condition || !condition());
return false;
}

View File

@ -1,6 +1,7 @@
#include <Common/checkStackSize.h>
#include <Common/Exception.h>
#include <base/scope_guard.h>
#include <base/defines.h> /// THREAD_SANITIZER
#include <pthread.h>
#include <cstdint>
@ -86,15 +87,24 @@ __attribute__((__weak__)) void checkStackSize()
uintptr_t int_frame_address = reinterpret_cast<uintptr_t>(frame_address);
uintptr_t int_stack_address = reinterpret_cast<uintptr_t>(stack_address);
#if !defined(THREAD_SANITIZER)
/// It's overkill to use more then half of stack.
static constexpr double STACK_SIZE_FREE_RATIO = 0.5;
#else
/// Under TSan recursion eats too much RAM, so half of stack is too much.
/// So under TSan only 5% of a stack is allowed (this is ~400K)
static constexpr double STACK_SIZE_FREE_RATIO = 0.05;
#endif
/// We assume that stack grows towards lower addresses. And that it starts to grow from the end of a chunk of memory of max_stack_size.
if (int_frame_address > int_stack_address + max_stack_size)
throw Exception("Logical error: frame address is greater than stack begin address", ErrorCodes::LOGICAL_ERROR);
size_t stack_size = int_stack_address + max_stack_size - int_frame_address;
size_t max_stack_size_allowed = max_stack_size * STACK_SIZE_FREE_RATIO;
/// Just check if we have already eat more than a half of stack size. It's a bit overkill (a half of stack size is wasted).
/// It's safe to assume that overflow in multiplying by two cannot occur.
if (stack_size * 2 > max_stack_size)
/// Just check if we have eat more than a STACK_SIZE_FREE_RATIO of stack size already.
if (stack_size > max_stack_size_allowed)
{
throw Exception(ErrorCodes::TOO_DEEP_RECURSION,
"Stack size too large. Stack address: {}, frame address: {}, stack size: {}, maximum stack size: {}",

View File

@ -58,20 +58,6 @@ CompressedReadBufferFromFile::CompressedReadBufferFromFile(std::unique_ptr<ReadB
}
CompressedReadBufferFromFile::CompressedReadBufferFromFile(
const std::string & path,
const ReadSettings & settings,
size_t estimated_size,
bool allow_different_codecs_)
: BufferWithOwnMemory<ReadBuffer>(0)
, p_file_in(createReadBufferFromFileBase(path, settings, estimated_size))
, file_in(*p_file_in)
{
compressed_in = &file_in;
allow_different_codecs = allow_different_codecs_;
}
void CompressedReadBufferFromFile::seek(size_t offset_in_compressed_file, size_t offset_in_decompressed_block)
{
/// Nothing to do if we already at required position

View File

@ -47,9 +47,6 @@ private:
public:
CompressedReadBufferFromFile(std::unique_ptr<ReadBufferFromFileBase> buf, bool allow_different_codecs_ = false);
CompressedReadBufferFromFile(
const std::string & path, const ReadSettings & settings, size_t estimated_size, bool allow_different_codecs_ = false);
/// Seek is lazy in some sense. We move position in compressed file_in to offset_in_compressed_file, but don't
/// read data into working_buffer and don't shit our position to offset_in_decompressed_block. Instead
/// we store this offset inside nextimpl_working_buffer_offset.

View File

@ -37,7 +37,7 @@ int main(int argc, char ** argv)
path,
[&]()
{
return createReadBufferFromFileBase(path, {}, 0);
return createReadBufferFromFileBase(path, {});
},
&cache
);
@ -56,7 +56,7 @@ int main(int argc, char ** argv)
path,
[&]()
{
return createReadBufferFromFileBase(path, {}, 0);
return createReadBufferFromFileBase(path, {});
},
&cache
);

View File

@ -631,6 +631,14 @@ LogEntryPtr Changelog::entryAt(uint64_t index)
return src;
}
LogEntryPtr Changelog::getLatestConfigChange() const
{
for (const auto & [_, entry] : logs)
if (entry->get_val_type() == nuraft::conf)
return entry;
return nullptr;
}
nuraft::ptr<nuraft::buffer> Changelog::serializeEntriesToBuffer(uint64_t index, int32_t count)
{
std::vector<nuraft::ptr<nuraft::buffer>> returned_logs;

View File

@ -102,6 +102,9 @@ public:
/// Last entry in log, or fake entry with term 0 if log is empty
LogEntryPtr getLastEntry() const;
/// Get entry with latest config in logstore
LogEntryPtr getLatestConfigChange() const;
/// Return log entries between [start, end)
LogEntriesPtr getLogEntriesBetween(uint64_t start_index, uint64_t end_index);

View File

@ -38,7 +38,8 @@ struct Settings;
M(Bool, quorum_reads, false, "Execute read requests as writes through whole RAFT consesus with similar speed", 0) \
M(Bool, force_sync, true, "Call fsync on each change in RAFT changelog", 0) \
M(Bool, compress_logs, true, "Write compressed coordination logs in ZSTD format", 0) \
M(Bool, compress_snapshots_with_zstd_format, true, "Write compressed snapshots in ZSTD format (instead of custom LZ4)", 0)
M(Bool, compress_snapshots_with_zstd_format, true, "Write compressed snapshots in ZSTD format (instead of custom LZ4)", 0) \
M(UInt64, configuration_change_tries_count, 20, "How many times we will try to apply configuration change (add/remove server) to the cluster", 0)
DECLARE_SETTINGS_TRAITS(CoordinationSettingsTraits, LIST_OF_COORDINATION_SETTINGS)

View File

@ -280,7 +280,6 @@ void KeeperDispatcher::initialize(const Poco::Util::AbstractConfiguration & conf
{
LOG_INFO(log, "Starting Keeper asynchronously, server will accept connections to Keeper when it will be ready");
}
}
catch (...)
{
@ -290,6 +289,8 @@ void KeeperDispatcher::initialize(const Poco::Util::AbstractConfiguration & conf
/// Start it after keeper server start
session_cleaner_thread = ThreadFromGlobalPool([this] { sessionCleanerTask(); });
update_configuration_thread = ThreadFromGlobalPool([this] { updateConfigurationThread(); });
updateConfiguration(config);
LOG_DEBUG(log, "Dispatcher initialized");
}
@ -325,6 +326,10 @@ void KeeperDispatcher::shutdown()
snapshots_queue.finish();
if (snapshot_thread.joinable())
snapshot_thread.join();
update_configuration_queue.finish();
if (update_configuration_thread.joinable())
update_configuration_thread.join();
}
if (server)
@ -505,4 +510,71 @@ int64_t KeeperDispatcher::getSessionID(int64_t session_timeout_ms)
return future.get();
}
void KeeperDispatcher::updateConfigurationThread()
{
while (true)
{
if (shutdown_called)
return;
try
{
if (!server->checkInit())
{
LOG_INFO(log, "Server still not initialized, will not apply configuration until initialization finished");
std::this_thread::sleep_for(std::chrono::milliseconds(5000));
continue;
}
ConfigUpdateAction action;
if (!update_configuration_queue.pop(action))
break;
/// We must wait this update from leader or apply it ourself (if we are leader)
bool done = false;
while (!done)
{
if (shutdown_called)
return;
if (isLeader())
{
server->applyConfigurationUpdate(action);
done = true;
}
else
{
done = server->waitConfigurationUpdate(action);
if (!done)
LOG_INFO(log, "Cannot wait for configuration update, maybe we become leader, or maybe update is invalid, will try to wait one more time");
}
}
}
catch (...)
{
tryLogCurrentException(__PRETTY_FUNCTION__);
}
}
}
void KeeperDispatcher::updateConfiguration(const Poco::Util::AbstractConfiguration & config)
{
auto diff = server->getConfigurationDiff(config);
if (diff.empty())
LOG_TRACE(log, "Configuration update triggered, but nothing changed for RAFT");
else if (diff.size() > 1)
LOG_WARNING(log, "Configuration changed for more than one server ({}) from cluster, it's strictly not recommended", diff.size());
else
LOG_DEBUG(log, "Configuration change size ({})", diff.size());
for (auto & change : diff)
{
bool push_result = update_configuration_queue.push(change);
if (!push_result)
throw Exception(ErrorCodes::SYSTEM_ERROR, "Cannot push configuration update to queue");
}
}
}

View File

@ -33,12 +33,16 @@ private:
CoordinationSettingsPtr coordination_settings;
using RequestsQueue = ConcurrentBoundedQueue<KeeperStorage::RequestForSession>;
using SessionToResponseCallback = std::unordered_map<int64_t, ZooKeeperResponseCallback>;
using UpdateConfigurationQueue = ConcurrentBoundedQueue<ConfigUpdateAction>;
/// Size depends on coordination settings
std::unique_ptr<RequestsQueue> requests_queue;
ResponsesQueue responses_queue;
SnapshotsQueue snapshots_queue{1};
/// More than 1k updates is definitely misconfiguration.
UpdateConfigurationQueue update_configuration_queue{1000};
std::atomic<bool> shutdown_called{false};
std::mutex session_to_response_callback_mutex;
@ -62,6 +66,8 @@ private:
ThreadFromGlobalPool session_cleaner_thread;
/// Dumping new snapshots to disk
ThreadFromGlobalPool snapshot_thread;
/// Apply or wait for configuration changes
ThreadFromGlobalPool update_configuration_thread;
/// RAFT wrapper.
std::unique_ptr<KeeperServer> server;
@ -80,6 +86,8 @@ private:
void sessionCleanerTask();
/// Thread create snapshots in the background
void snapshotThread();
/// Thread apply or wait configuration changes from leader
void updateConfigurationThread();
void setResponse(int64_t session_id, const Coordination::ZooKeeperResponsePtr & response);
@ -107,6 +115,10 @@ public:
return server && server->checkInit();
}
/// Registered in ConfigReloader callback. Add new configuration changes to
/// update_configuration_queue. Keeper Dispatcher apply them asynchronously.
void updateConfiguration(const Poco::Util::AbstractConfiguration & config);
/// Shutdown internal keeper parts (server, state machine, log storage, etc)
void shutdown();

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