mirror of
https://github.com/ClickHouse/ClickHouse.git
synced 2024-12-11 00:42:29 +00:00
107 KiB
107 KiB
ClickHouse release 18.14.11, 2018-10-29
Bug fixes:
- Fixed the error
Block structure mismatch in UNION stream: different number of columns
in LIMIT queries. #2156 - Fixed errors when merging data in tables containing arrays inside Nested structures. #3397
- Fixed incorrect query results if the
merge_tree_uniform_read_distribution
setting is disabled (it is enabled by default). #3429 - Fixed an error on inserts to a Distributed table in Native format. #3411
ClickHouse release 18.14.10, 2018-10-23
- The
compile_expressions
setting (JIT compilation of expressions) is disabled by default. #3410 - The
enable_optimize_predicate_expression
setting is disabled by default.
ClickHouse release 18.14.9, 2018-10-16
New features:
- The
WITH CUBE
modifier forGROUP BY
(the alternative syntaxGROUP BY CUBE(...)
is also available). #3172 - Added the
formatDateTime
function. Alexandr Krasheninnikov - Added the
JDBC
table engine andjdbc
table function (requires installing clickhouse-jdbc-bridge). Alexandr Krasheninnikov - Added functions for working with the ISO week number:
toISOWeek
,toISOYear
,toStartOfISOYear
, andtoDayOfYear
. #3146 - Now you can use
Nullable
columns forMySQL
andODBC
tables. #3362 - Nested data structures can be read as nested objects in
JSONEachRow
format. Added theinput_format_import_nested_json
setting. Veloman Yunkan - Parallel processing is available for many
MATERIALIZED VIEW
s when inserting data. See theparallel_view_processing
setting. Marek Vavruša - Added the
SYSTEM FLUSH LOGS
query (forced log flushes to system tables such asquery_log
) #3321 - Now you can use pre-defined
database
andtable
macros when declaringReplicated
tables. #3251 - Added the ability to read
Decimal
type values in engineering notation (indicating powers of ten). #3153
Experimental features:
- Optimization of the GROUP BY clause for
LowCardinality data types.
#3138 - Optimized calculation of expressions for
LowCardinality data types.
#3200
Improvements:
- Significantly reduced memory consumption for requests with
ORDER BY
andLIMIT
. See themax_bytes_before_remerge_sort
setting. #3205 - In the absence of
JOIN
(LEFT
,INNER
, ...),INNER JOIN
is assumed. #3147 - Qualified asterisks work correctly in queries with
JOIN
. Winter Zhang - The
ODBC
table engine correctly chooses the method for quoting identifiers in the SQL dialect of a remote database. Alexandr Krasheninnikov - The
compile_expressions
setting (JIT compilation of expressions) is enabled by default. - Fixed behavior for simultaneous DROP DATABASE/TABLE IF EXISTS and CREATE DATABASE/TABLE IF NOT EXISTS. Previously, a
CREATE DATABASE ... IF NOT EXISTS
query could return the error message "File ... already exists", and theCREATE TABLE ... IF NOT EXISTS
andDROP TABLE IF EXISTS
queries could returnTable ... is creating or attaching right now
. #3101 - LIKE and IN expressions with a constant right half are passed to the remote server when querying from MySQL or ODBC tables. #3182
- Comparisons with constant expressions in a WHERE clause are passed to the remote server when querying from MySQL and ODBC tables. Previously, only comparisons with constants were passed. #3182
- Correct calculation of row width in the terminal for
Pretty
formats, including strings with hieroglyphs. Amos Bird. ON CLUSTER
can be specified forALTER UPDATE
queries.- Improved performance for reading data in
JSONEachRow
format. #3332 - Added synonyms for the
LENGTH
andCHARACTER_LENGTH
functions for compatibility. TheCONCAT
function is no longer case-sensitive. #3306 - Added the
TIMESTAMP
synonym for theDateTime
type. #3390 - There is always space reserved for query_id in the server logs, even if the log line is not related to a query. This makes it easier to parse server text logs with third-party tools.
- Memory consumption by a query is logged when it exceeds the next level of an integer number of gigabytes. #3205
- Added compatibility mode for the case when the client library that uses the Native protocol sends fewer columns by mistake than the server expects for the INSERT query. This scenario was possible when using the clickhouse-cpp library. Previously, this scenario caused the server to crash. #3171
- In a user-defined WHERE expression in
clickhouse-copier
, you can now use apartition_key
alias (for additional filtering by source table partition). This is useful if the partitioning scheme changes during copying, but only changes slightly. #3166 - The workflow of the
Kafka
engine has been moved to a background thread pool in order to automatically reduce the speed of data reading at high loads. Marek Vavruša. - Support for reading
Tuple
andNested
values of structures likestruct
in theCap'n'Proto format
. Marek Vavruša - The list of top-level domains for the
firstSignificantSubdomain
function now includes the domainbiz
. decaseal - In the configuration of external dictionaries,
null_value
is interpreted as the value of the default data type. #3330 - Support for the
intDiv
andintDivOrZero
functions forDecimal
. b48402e8 - Support for the
Date
,DateTime
,UUID
, andDecimal
types as a key for thesumMap
aggregate function. #3281 - Support for the
Decimal
data type in external dictionaries. #3324 - Support for the
Decimal
data type inSummingMergeTree
tables. #3348 - Added specializations for
UUID
inif
. #3366 - Reduced the number of
open
andclose
system calls when reading from aMergeTree table
. #3283 - A
TRUNCATE TABLE
query can be executed on any replica (the query is passed to the leader replica). Kirill Shvakov
Bug fixes:
- Fixed an issue with
Dictionary
tables forrange_hashed
dictionaries. This error occurred in version 18.12.17. #1702 - Fixed an error when loading
range_hashed
dictionaries (the messageUnsupported type Nullable (...)
). This error occurred in version 18.12.17. #3362 - Fixed errors in the
pointInPolygon
function due to the accumulation of inaccurate calculations for polygons with a large number of vertices located close to each other. #3331 #3341 - If after merging data parts, the checksum for the resulting part differs from the result of the same merge in another replica, the result of the merge is deleted and the data part is downloaded from the other replica (this is the correct behavior). But after downloading the data part, it couldn't be added to the working set because of an error that the part already exists (because the data part was deleted with some delay after the merge). This led to cyclical attempts to download the same data. #3194
- Fixed incorrect calculation of total memory consumption by queries (because of incorrect calculation, the
max_memory_usage_for_all_queries
setting worked incorrectly and theMemoryTracking
metric had an incorrect value). This error occurred in version 18.12.13. Marek Vavruša - Fixed the functionality of
CREATE TABLE ... ON CLUSTER ... AS SELECT ...
This error occurred in version 18.12.13. #3247 - Fixed unnecessary preparation of data structures for
JOIN
s on the server that initiates the request if theJOIN
is only performed on remote servers. #3340 - Fixed bugs in the
Kafka
engine: deadlocks after exceptions when starting to read data, and locks upon completion Marek Vavruša. - For
Kafka
tables, the optionalschema
parameter was not passed (the schema of theCap'n'Proto
format). Vojtech Splichal - If the ensemble of ZooKeeper servers has servers that accept the connection but then immediately close it instead of responding to the handshake, ClickHouse chooses to connect another server. Previously, this produced the error
Cannot read all data. Bytes read: 0. Bytes expected: 4.
and the server couldn't start. 8218cf3a - If the ensemble of ZooKeeper servers contains servers for which the DNS query returns an error, these servers are ignored. 17b8e209
- Fixed type conversion between
Date
andDateTime
when inserting data in theVALUES
format (ifinput_format_values_interpret_expressions = 1
). Previously, the conversion was performed between the numerical value of the number of days in Unix Epoch time and the Unix timestamp, which led to unexpected results. #3229 - Corrected type conversion between
Decimal
and integer numbers. #3211 - Fixed errors in the
enable_optimize_predicate_expression
setting. Winter Zhang - Fixed a parsing error in CSV format with floating-point numbers if a non-default CSV separator is used, such as
;
#3155 - Fixed the
arrayCumSumNonNegative
function (it does not accumulate negative values if the accumulator is less than zero). Aleksey Studnev - Fixed how
Merge
tables work on top ofDistributed
tables when usingPREWHERE
. #3165 - Bug fixes in the
ALTER UPDATE
query. - Fixed bugs in the
odbc
table function that appeared in version 18.12. #3197 - Fixed the operation of aggregate functions with
StateArray
combinators. #3188 - Fixed a crash when dividing a
Decimal
value by zero. 69dd6609 - Fixed output of types for operations using
Decimal
and integer arguments. #3224 - Fixed the segfault during
GROUP BY
onDecimal128
. 3359ba06 - The
log_query_threads
setting (logging information about each thread of query execution) now takes effect only if thelog_queries
option (logging information about queries) is set to 1. Since thelog_query_threads
option is enabled by default, information about threads was previously logged even if query logging was disabled. #3241 - Fixed an error in the distributed operation of the quantiles aggregate function (the error message
Not found column quantile...
). 292a8855 - Fixed the compatibility problem when working on a cluster of version 18.12.17 servers and older servers at the same time. For distributed queries with GROUP BY keys of both fixed and non-fixed length, if there was a large amount of data to aggregate, the returned data was not always fully aggregated (two different rows contained the same aggregation keys). #3254
- Fixed handling of substitutions in
clickhouse-performance-test
, if the query contains only part of the substitutions declared in the test. #3263 - Fixed an error when using
FINAL
withPREWHERE
. #3298 - Fixed an error when using
PREWHERE
over columns that were added duringALTER
. #3298 - Added a check for the absence of
arrayJoin
forDEFAULT
andMATERIALIZED
expressions. Previously,arrayJoin
led to an error when inserting data. #3337 - Added a check for the absence of
arrayJoin
in aPREWHERE
clause. Previously, this led to messages likeSize ... doesn't match
orUnknown compression method
when executing queries. #3357 - Fixed segfault that could occur in rare cases after optimization that replaced AND chains from equality evaluations with the corresponding IN expression. liuyimin-bytedance
- Minor corrections to
clickhouse-benchmark
: previously, client information was not sent to the server; now the number of queries executed is calculated more accurately when shutting down and for limiting the number of iterations. #3351 #3352
Backward incompatible changes:
- Removed the
allow_experimental_decimal_type
option. TheDecimal
data type is available for default use. #3329
ClickHouse release 18.12.17, 2018-09-16
New features:
invalidate_query
(the ability to specify a query to check whether an external dictionary needs to be updated) is implemented for theclickhouse
source. #3126- Added the ability to use
UInt*
,Int*
, andDateTime
data types (along with theDate
type) as arange_hashed
external dictionary key that defines the boundaries of ranges. NowNULL
can be used to designate an open range. Vasily Nemkov - The
Decimal
type now supportsvar*
andstddev*
aggregate functions. #3129 - The
Decimal
type now supports mathematical functions (exp
,sin
and so on.) #3129 - The
system.part_log
table now has thepartition_id
column. #3089
Bug fixes:
Merge
now works correctly onDistributed
tables. Winter Zhang- Fixed incompatibility (unnecessary dependency on the
glibc
version) that made it impossible to run ClickHouse onUbuntu Precise
and older versions. The incompatibility arose in version 18.12.13. #3130 - Fixed errors in the
enable_optimize_predicate_expression
setting. Winter Zhang - Fixed a minor issue with backwards compatibility that appeared when working with a cluster of replicas on versions earlier than 18.12.13 and simultaneously creating a new replica of a table on a server with a newer version (shown in the message
Can not clone replica, because the ... updated to new ClickHouse version
, which is logical, but shouldn't happen). #3122
Backward incompatible changes:
- The
enable_optimize_predicate_expression
option is enabled by default (which is rather optimistic). If query analysis errors occur that are related to searching for the column names, setenable_optimize_predicate_expression
to 0. Winter Zhang
ClickHouse release 18.12.14, 2018-09-13
New features:
- Added support for
ALTER UPDATE
queries. #3035 - Added the
allow_ddl
option, which restricts the user's access to DDL queries. #3104 - Added the
min_merge_bytes_to_use_direct_io
option forMergeTree
engines, which allows you to set a threshold for the total size of the merge (when above the threshold, data part files will be handled using O_DIRECT). #3117 - The
system.merges
system table now contains thepartition_id
column. #3099
Improvements
- If a data part remains unchanged during mutation, it isn't downloaded by replicas. #3103
- Autocomplete is available for names of settings when working with
clickhouse-client
. #3106
Bug fixes:
- Added a check for the sizes of arrays that are elements of
Nested
type fields when inserting. #3118 - Fixed an error updating external dictionaries with the
ODBC
source andhashed
storage. This error occurred in version 18.12.13. - Fixed a crash when creating a temporary table from a query with an
IN
condition. Winter Zhang - Fixed an error in aggregate functions for arrays that can have
NULL
elements. Winter Zhang
ClickHouse release 18.12.13, 2018-09-10
New features:
- Added the
DECIMAL(digits, scale)
data type (Decimal32(scale)
,Decimal64(scale)
,Decimal128(scale)
). To enable it, use the settingallow_experimental_decimal_type
. #2846 #2970 #3008 #3047 - New
WITH ROLLUP
modifier forGROUP BY
(alternative syntax:GROUP BY ROLLUP(...)
). #2948 - In requests with JOIN, the star character expands to a list of columns in all tables, in compliance with the SQL standard. You can restore the old behavior by setting
asterisk_left_columns_only
to 1 on the user configuration level. Winter Zhang - Added support for JOIN with table functions. Winter Zhang
- Autocomplete by pressing Tab in clickhouse-client. Sergey Shcherbin
- Ctrl+C in clickhouse-client clears a query that was entered. #2877
- Added the
join_default_strictness
setting (values:"
,'any'
,'all'
). This allows you to not specifyANY
orALL
forJOIN
. #2982 - Each line of the server log related to query processing shows the query ID. #2482
- Now you can get query execution logs in clickhouse-client (use the
send_logs_level
setting). With distributed query processing, logs are cascaded from all the servers. #2482 - The
system.query_log
andsystem.processes
(SHOW PROCESSLIST
) tables now have information about all changed settings when you run a query (the nested structure of theSettings
data). Added thelog_query_settings
setting. #2482 - The
system.query_log
andsystem.processes
tables now show information about the number of threads that are participating in query execution (see thethread_numbers
column). #2482 - Added
ProfileEvents
counters that measure the time spent on reading and writing over the network and reading and writing to disk, the number of network errors, and the time spent waiting when network bandwidth is limited. #2482 - Added
ProfileEvents
counters that contain the system metrics from rusage (you can use them to get information about CPU usage in userspace and the kernel, page faults, and context switches), as well as taskstats metrics (use these to obtain information about I/O wait time, CPU wait time, and the amount of data read and recorded, both with and without page cache). #2482 - The
ProfileEvents
counters are applied globally and for each query, as well as for each query execution thread, which allows you to profile resource consumption by query in detail. #2482 - Added the
system.query_thread_log
table, which contains information about each query execution thread. Added thelog_query_threads
setting. #2482 - The
system.metrics
andsystem.events
tables now have built-in documentation. #3016 - Added the
arrayEnumerateDense
function. Amos Bird - Added the
arrayCumSumNonNegative
andarrayDifference
functions. Aleksey Studnev - Added the
retention
aggregate function. Sundy Li - Now you can add (merge) states of aggregate functions by using the plus operator, and multiply the states of aggregate functions by a nonnegative constant. #3062 #3034
- Tables in the MergeTree family now have the virtual column
_partition_id
. #3089
Experimental features:
- Added the
LowCardinality(T)
data type. This data type automatically creates a local dictionary of values and allows data processing without unpacking the dictionary. #2830 - Added a cache of JIT-compiled functions and a counter for the number of uses before compiling. To JIT compile expressions, enable the
compile_expressions
setting. #2990 #3077
Improvements:
- Fixed the problem with unlimited accumulation of the replication log when there are abandoned replicas. Added an effective recovery mode for replicas with a long lag.
- Improved performance of
GROUP BY
with multiple aggregation fields when one of them is string and the others are fixed length. - Improved performance when using
PREWHERE
and with implicit transfer of expressions inPREWHERE
. - Improved parsing performance for text formats (
CSV
,TSV
). Amos Bird #2980 - Improved performance of reading strings and arrays in binary formats. Amos Bird
- Increased performance and reduced memory consumption for queries to
system.tables
andsystem.columns
when there is a very large number of tables on a single server. #2953 - Fixed a performance problem in the case of a large stream of queries that result in an error (the
_dl_addr
function is visible inperf top
, but the server isn't using much CPU). #2938 - Conditions are cast into the View (when
enable_optimize_predicate_expression
is enabled). Winter Zhang - Improvements to the functionality for the
UUID
data type. #3074 #2985 - The
UUID
data type is supported in The-Alchemist dictionaries. #2822 - The
visitParamExtractRaw
function works correctly with nested structures. Winter Zhang - When the
input_format_skip_unknown_fields
setting is enabled, object fields inJSONEachRow
format are skipped correctly. BlahGeek - For a
CASE
expression with conditions, you can now omitELSE
, which is equivalent toELSE NULL
. #2920 - The operation timeout can now be configured when working with ZooKeeper. urykhy
- You can specify an offset for
LIMIT n, m
asLIMIT n OFFSET m
. #2840 - You can use the
SELECT TOP n
syntax as an alternative forLIMIT
. #2840 - Increased the size of the queue to write to system tables, so the
SystemLog parameter queue is full
error doesn't happen as often. - The
windowFunnel
aggregate function now supports events that meet multiple conditions. Amos Bird - Duplicate columns can be used in a
USING
clause forJOIN
. #3006 Pretty
formats now have a limit on column alignment by width. Use theoutput_format_pretty_max_column_pad_width
setting. If a value is wider, it will still be displayed in its entirety, but the other cells in the table will not be too wide. #3003- The
odbc
table function now allows you to specify the database/schema name. Amos Bird - Added the ability to use a username specified in the
clickhouse-client
config file. Vladimir Kozbin - The
ZooKeeperExceptions
counter has been split into three counters:ZooKeeperUserExceptions
,ZooKeeperHardwareExceptions
, andZooKeeperOtherExceptions
. ALTER DELETE
queries work for materialized views.- Added randomization when running the cleanup thread periodically for
ReplicatedMergeTree
tables in order to avoid periodic load spikes when there are a very large number ofReplicatedMergeTree
tables. - Support for
ATTACH TABLE ... ON CLUSTER
queries. #3025
Bug fixes:
- Fixed an issue with
Dictionary
tables (throws theSize of offsets doesn't match size of column
orUnknown compression method
exception). This bug appeared in version 18.10.3. #2913 - Fixed a bug when merging
CollapsingMergeTree
tables if one of the data parts is empty (these parts are formed during merge orALTER DELETE
if all data was deleted), and thevertical
algorithm was used for the merge. #3049 - Fixed a race condition during
DROP
orTRUNCATE
forMemory
tables with a simultaneousSELECT
, which could lead to server crashes. This bug appeared in version 1.1.54388. #3038 - Fixed the possibility of data loss when inserting in
Replicated
tables if theSession is expired
error is returned (data loss can be detected by theReplicatedDataLoss
metric). This error occurred in version 1.1.54378. #2939 #2949 #2964 - Fixed a segfault during
JOIN ... ON
. #3000 - Fixed the error searching column names when the
WHERE
expression consists entirely of a qualified column name, such asWHERE table.column
. #2994 - Fixed the "Not found column" error that occurred when executing distributed queries if a single column consisting of an IN expression with a subquery is requested from a remote server. #3087
- Fixed the
Block structure mismatch in UNION stream: different number of columns
error that occurred for distributed queries if one of the shards is local and the other is not, and optimization of the move toPREWHERE
is triggered. #2226 #3037 #3055 #3065 #3073 #3090 #3093 - Fixed the
pointInPolygon
function for certain cases of non-convex polygons. #2910 - Fixed the incorrect result when comparing
nan
with integers. #3024 - Fixed an error in the
zlib-ng
library that could lead to segfault in rare cases. #2854 - Fixed a memory leak when inserting into a table with
AggregateFunction
columns, if the state of the aggregate function is not simple (allocates memory separately), and if a single insertion request results in multiple small blocks. #3084 - Fixed a race condition when creating and deleting the same
Buffer
orMergeTree
table simultaneously. - Fixed the possibility of a segfault when comparing tuples made up of certain non-trivial types, such as tuples. #2989
- Fixed the possibility of a segfault when running certain
ON CLUSTER
queries. Winter Zhang - Fixed an error in the
arrayDistinct
function forNullable
array elements. #2845 #2937 - The
enable_optimize_predicate_expression
option now correctly supports cases withSELECT *
. Winter Zhang - Fixed the segfault when re-initializing the ZooKeeper session. #2917
- Fixed potential blocking when working with ZooKeeper.
- Fixed incorrect code for adding nested data structures in a
SummingMergeTree
. - When allocating memory for states of aggregate functions, alignment is correctly taken into account, which makes it possible to use operations that require alignment when implementing states of aggregate functions. chenxing-xc
Security fix:
- Safe use of ODBC data sources. Interaction with ODBC drivers uses a separate
clickhouse-odbc-bridge
process. Errors in third-party ODBC drivers no longer cause problems with server stability or vulnerabilities. #2828 #2879 #2886 #2893 #2921 - Fixed incorrect validation of the file path in the
catBoostPool
table function. #2894 - The contents of system tables (
tables
,databases
,parts
,columns
,parts_columns
,merges
,mutations
,replicas
, andreplication_queue
) are filtered according to the user's configured access to databases (allow_databases
). Winter Zhang
Backward incompatible changes:
- In requests with JOIN, the star character expands to a list of columns in all tables, in compliance with the SQL standard. You can restore the old behavior by setting
asterisk_left_columns_only
to 1 on the user configuration level.
Build changes:
- Most integration tests can now be run by commit.
- Code style checks can also be run by commit.
- The
memcpy
implementation is chosen correctly when building on CentOS7/Fedora. Etienne Champetier - When using clang to build, some warnings from
-Weverything
have been added, in addition to the regular-Wall-Wextra -Werror
. #2957 - Debugging the build uses the
jemalloc
debug option. - The interface of the library for interacting with ZooKeeper is declared abstract. #2950
ClickHouse release 18.10.3, 2018-08-13
New features:
- HTTPS can be used for replication. #2760
- Added the functions
murmurHash2_64
,murmurHash3_32
,murmurHash3_64
, andmurmurHash3_128
in addition to the existingmurmurHash2_32
. #2791 - Support for Nullable types in the ClickHouse ODBC driver (
ODBCDriver2
output format). #2834 - Support for
UUID
in the key columns.
Improvements:
- Clusters can be removed without restarting the server when they are deleted from the config files. #2777
- External dictionaries can be removed without restarting the server when they are removed from config files. #2779
- Added
SETTINGS
support for theKafka
table engine. Alexander Marshalov - Improvements for the
UUID
data type (not yet complete). #2618 - Support for empty parts after merges in the
SummingMergeTree
,CollapsingMergeTree
andVersionedCollapsingMergeTree
engines. #2815 - Old records of completed mutations are deleted (
ALTER DELETE
). #2784 - Added the
system.merge_tree_settings
table. Kirill Shvakov - The
system.tables
table now has dependency columns:dependencies_database
anddependencies_table
. Winter Zhang - Added the
max_partition_size_to_drop
config option. #2782 - Added the
output_format_json_escape_forward_slashes
option. Alexander Bocharov - Added the
max_fetch_partition_retries_count
setting. #2831 - Added the
prefer_localhost_replica
setting for disabling the preference for a local replica and going to a local replica without inter-process interaction. #2832 - The
quantileExact
aggregate function returnsnan
in the case of aggregation on an emptyFloat32
orFloat64
set. Sundy Li
Bug fixes:
- Removed unnecessary escaping of the connection string parameters for ODBC, which made it impossible to establish a connection. This error occurred in version 18.6.0.
- Fixed the logic for processing
REPLACE PARTITION
commands in the replication queue. If there are twoREPLACE
commands for the same partition, the incorrect logic could cause one of them to remain in the replication queue and not be executed. #2814 - Fixed a merge bug when all data parts were empty (parts that were formed from a merge or from
ALTER DELETE
if all data was deleted). This bug appeared in version 18.1.0. #2930 - Fixed an error for concurrent
Set
orJoin
. Amos Bird - Fixed the
Block structure mismatch in UNION stream: different number of columns
error that occurred forUNION ALL
queries inside a sub-query if one of theSELECT
queries contains duplicate column names. Winter Zhang - Fixed a memory leak if an exception occurred when connecting to a MySQL server.
- Fixed incorrect clickhouse-client response code in case of a request error.
- Fixed incorrect behavior of materialized views containing DISTINCT. #2795
Backward incompatible changes
- Removed support for CHECK TABLE queries for Distributed tables.
Build changes:
- The allocator has been replaced:
jemalloc
is now used instead oftcmalloc
. In some scenarios, this increases speed up to 20%. However, there are queries that have slowed by up to 20%. Memory consumption has been reduced by approximately 10% in some scenarios, with improved stability. With highly competitive loads, CPU usage in userspace and in system shows just a slight increase. #2773 - Use of libressl from a submodule. #1983 #2807
- Use of unixodbc from a submodule. #2789
- Use of mariadb-connector-c from a submodule. #2785
- Added functional test files to the repository that depend on the availability of test data (for the time being, without the test data itself).
ClickHouse release 18.6.0, 2018-08-02
New features:
- Added support for ON expressions for the JOIN ON syntax:
JOIN ON Expr([table.]column ...) = Expr([table.]column, ...) [AND Expr([table.]column, ...) = Expr([table.]column, ...) ...]
The expression must be a chain of equalities joined by the AND operator. Each side of the equality can be an arbitrary expression over the columns of one of the tables. The use of fully qualified column names is supported (table.name
,database.table.name
,table_alias.name
,subquery_alias.name
) for the right table. #2742 - HTTPS can be enabled for replication. #2760
Improvements:
- The server passes the patch component of its version to the client. Data about the patch version component is in
system.processes
andquery_log
. #2646
ClickHouse release 18.5.1, 2018-07-31
New features:
- Added the hash function
murmurHash2_32
#2756.
Improvements:
- Now you can use the
from_env
#2741 attribute to set values in config files from environment variables. - Added case-insensitive versions of the
coalesce
,ifNull
, andnullIf functions
#2752.
Bug fixes:
- Fixed a possible bug when starting a replica #2759.
ClickHouse release 18.4.0, 2018-07-28
New features:
- Added system tables:
formats
,data_type_families
,aggregate_function_combinators
,table_functions
,table_engines
,collations
#2721. - Added the ability to use a table function instead of a table as an argument of a
remote
orcluster table function
#2708. - Support for
HTTP Basic
authentication in the replication protocol #2727. - The
has
function now allows searching for a numeric value in an array ofEnum
values Maxim Khrisanfov. - Support for adding arbitrary message separators when reading from
Kafka
Amos Bird.
Improvements:
- The
ALTER TABLE t DELETE WHERE
query does not rewrite data parts that were not affected by the WHERE condition #2694. - The
use_minimalistic_checksums_in_zookeeper
option forReplicatedMergeTree
tables is enabled by default. This setting was added in version 1.1.54378, 2018-04-16. Versions that are older than 1.1.54378 can no longer be installed. - Support for running
KILL
andOPTIMIZE
queries that specifyON CLUSTER
Winter Zhang.
Bug fixes:
- Fixed the error
Column ... is not under an aggregate function and not in GROUP BY
for aggregation with an IN expression. This bug appeared in version 18.1.0. (bbdd780b) - Fixed a bug in the
windowFunnel aggregate function
Winter Zhang. - Fixed a bug in the
anyHeavy
aggregate function (a2101df2) - Fixed server crash when using the
countArray()
aggregate function.
Backward incompatible changes:
- Parameters for
Kafka
engine was changed fromKafka(kafka_broker_list, kafka_topic_list, kafka_group_name, kafka_format[, kafka_schema, kafka_num_consumers])
toKafka(kafka_broker_list, kafka_topic_list, kafka_group_name, kafka_format[, kafka_row_delimiter, kafka_schema, kafka_num_consumers])
. If your tables usekafka_schema
orkafka_num_consumers
parameters, you have to manually edit the metadata filespath/metadata/database/table.sql
and addkafka_row_delimiter
parameter with''
value.
ClickHouse release 18.1.0, 2018-07-23
New features:
- Support for the
ALTER TABLE t DELETE WHERE
query for non-replicated MergeTree tables (#2634). - Support for arbitrary types for the
uniq*
family of aggregate functions (#2010). - Support for arbitrary types in comparison operators (#2026).
- The
users.xml
file allows setting a subnet mask in the format10.0.0.1/255.255.255.0
. This is necessary for using masks for IPv6 networks with zeros in the middle (#2637). - Added the
arrayDistinct
function (#2670). - The SummingMergeTree engine can now work with AggregateFunction type columns (Constantin S. Pan).
Improvements:
- Changed the numbering scheme for release versions. Now the first part contains the year of release (A.D., Moscow timezone, minus 2000), the second part contains the number for major changes (increases for most releases), and the third part is the patch version. Releases are still backwards compatible, unless otherwise stated in the changelog.
- Faster conversions of floating-point numbers to a string (Amos Bird).
- If some rows were skipped during an insert due to parsing errors (this is possible with the
input_allow_errors_num
andinput_allow_errors_ratio
settings enabled), the number of skipped rows is now written to the server log (Leonardo Cecchi).
Bug fixes:
- Fixed the TRUNCATE command for temporary tables (Amos Bird).
- Fixed a rare deadlock in the ZooKeeper client library that occurred when there was a network error while reading the response (c315200).
- Fixed an error during a CAST to Nullable types (#1322).
- Fixed the incorrect result of the
maxIntersection()
function when the boundaries of intervals coincided (Michael Furmur). - Fixed incorrect transformation of the OR expression chain in a function argument (chenxing-xc).
- Fixed performance degradation for queries containing
IN (subquery)
expressions inside another subquery (#2571). - Fixed incompatibility between servers with different versions in distributed queries that use a
CAST
function that isn't in uppercase letters (fe8c4d6). - Added missing quoting of identifiers for queries to an external DBMS (#2635).
Backward incompatible changes:
- Converting a string containing the number zero to DateTime does not work. Example:
SELECT toDateTime('0')
. This is also the reason thatDateTime DEFAULT '0'
does not work in tables, as well as<null_value>0</null_value>
in dictionaries. Solution: replace0
with0000-00-00 00:00:00
.
ClickHouse release 1.1.54394, 2018-07-12
New features:
- Added the
histogram
aggregate function (Mikhail Surin). - Now
OPTIMIZE TABLE ... FINAL
can be used without specifying partitions forReplicatedMergeTree
(Amos Bird).
Bug fixes:
- Fixed a problem with a very small timeout for sockets (one second) for reading and writing when sending and downloading replicated data, which made it impossible to download larger parts if there is a load on the network or disk (it resulted in cyclical attempts to download parts). This error occurred in version 1.1.54388.
- Fixed issues when using chroot in ZooKeeper if you inserted duplicate data blocks in the table.
- The
has
function now works correctly for an array with Nullable elements (#2115). - The
system.tables
table now works correctly when used in distributed queries. Themetadata_modification_time
andengine_full
columns are now non-virtual. Fixed an error that occurred if only these columns were requested from the table. - Fixed how an empty
TinyLog
table works after inserting an empty data block (#2563). - The
system.zookeeper
table works if the value of the node in ZooKeeper is NULL.
ClickHouse release 1.1.54390, 2018-07-06
New features:
- Queries can be sent in
multipart/form-data
format (in thequery
field), which is useful if external data is also sent for query processing (Olga Hvostikova). - Added the ability to enable or disable processing single or double quotes when reading data in CSV format. You can configure this in the
format_csv_allow_single_quotes
andformat_csv_allow_double_quotes
settings (Amos Bird). - Now
OPTIMIZE TABLE ... FINAL
can be used without specifying the partition for non-replicated variants ofMergeTree
(Amos Bird).
Improvements:
- Improved performance, reduced memory consumption, and correct memory consumption tracking with use of the IN operator when a table index could be used (#2584).
- Removed redundant checking of checksums when adding a data part. This is important when there are a large number of replicas, because in these cases the total number of checks was equal to N^2.
- Added support for
Array(Tuple(...))
arguments for thearrayEnumerateUniq
function (#2573). - Added
Nullable
support for therunningDifference
function (#2594). - Improved query analysis performance when there is a very large number of expressions (#2572).
- Faster selection of data parts for merging in
ReplicatedMergeTree
tables. Faster recovery of the ZooKeeper session (#2597). - The
format_version.txt
file forMergeTree
tables is re-created if it is missing, which makes sense if ClickHouse is launched after copying the directory structure without files (Ciprian Hacman).
Bug fixes:
- Fixed a bug when working with ZooKeeper that could make it impossible to recover the session and readonly states of tables before restarting the server.
- Fixed a bug when working with ZooKeeper that could result in old nodes not being deleted if the session is interrupted.
- Fixed an error in the
quantileTDigest
function for Float arguments (this bug was introduced in version 1.1.54388) (Mikhail Surin). - Fixed a bug in the index for MergeTree tables if the primary key column is located inside the function for converting types between signed and unsigned integers of the same size (#2603).
- Fixed segfault if
macros
are used but they aren't in the config file (#2570). - Fixed switching to the default database when reconnecting the client (#2583).
- Fixed a bug that occurred when the
use_index_for_in_with_subqueries
setting was disabled.
Security fix:
- Sending files is no longer possible when connected to MySQL (
LOAD DATA LOCAL INFILE
).
ClickHouse release 1.1.54388, 2018-06-28
New features:
- Support for the
ALTER TABLE t DELETE WHERE
query for replicated tables. Added thesystem.mutations
table to track progress of this type of queries. - Support for the
ALTER TABLE t [REPLACE|ATTACH] PARTITION
query for *MergeTree tables. - Support for the
TRUNCATE TABLE
query (Winter Zhang) - Several new
SYSTEM
queries for replicated tables (RESTART REPLICAS
,SYNC REPLICA
,[STOP|START] [MERGES|FETCHES|SENDS REPLICATED|REPLICATION QUEUES]
). - Added the ability to write to a table with the MySQL engine and the corresponding table function (sundy-li).
- Added the
url()
table function and theURL
table engine (Alexander Sapin). - Added the
windowFunnel
aggregate function (sundy-li). - New
startsWith
andendsWith
functions for strings (Vadim Plakhtinsky). - The
numbers()
table function now allows you to specify the offset (Winter Zhang). - The password to
clickhouse-client
can be entered interactively. - Server logs can now be sent to syslog (Alexander Krasheninnikov).
- Support for logging in dictionaries with a shared library source (Alexander Sapin).
- Support for custom CSV delimiters (Ivan Zhukov)
- Added the
date_time_input_format
setting. If you switch this setting to'best_effort'
, DateTime values will be read in a wide range of formats. - Added the
clickhouse-obfuscator
utility for data obfuscation. Usage example: publishing data used in performance tests.
Experimental features:
- Added the ability to calculate
and
arguments only where they are needed (Anastasia Tsarkova) - JIT compilation to native code is now available for some expressions (pyos).
Bug fixes:
- Duplicates no longer appear for a query with
DISTINCT
andORDER BY
. - Queries with
ARRAY JOIN
andarrayFilter
no longer return an incorrect result. - Fixed an error when reading an array column from a Nested structure (#2066).
- Fixed an error when analyzing queries with a HAVING clause like
HAVING tuple IN (...)
. - Fixed an error when analyzing queries with recursive aliases.
- Fixed an error when reading from ReplacingMergeTree with a condition in PREWHERE that filters all rows (#2525).
- User profile settings were not applied when using sessions in the HTTP interface.
- Fixed how settings are applied from the command line parameters in clickhouse-local.
- The ZooKeeper client library now uses the session timeout received from the server.
- Fixed a bug in the ZooKeeper client library when the client waited for the server response longer than the timeout.
- Fixed pruning of parts for queries with conditions on partition key columns (#2342).
- Merges are now possible after
CLEAR COLUMN IN PARTITION
(#2315). - Type mapping in the ODBC table function has been fixed (sundy-li).
- Type comparisons have been fixed for
DateTime
with and without the time zone (Alexander Bocharov). - Fixed syntactic parsing and formatting of the
CAST
operator. - Fixed insertion into a materialized view for the Distributed table engine (Babacar Diassé).
- Fixed a race condition when writing data from the
Kafka
engine to materialized views (Yangkuan Liu). - Fixed SSRF in the remote() table function.
- Fixed exit behavior of
clickhouse-client
in multiline mode (#2510).
Improvements:
- Background tasks in replicated tables are now performed in a thread pool instead of in separate threads (Silviu Caragea).
- Improved LZ4 compression performance.
- Faster analysis for queries with a large number of JOINs and sub-queries.
- The DNS cache is now updated automatically when there are too many network errors.
- Table inserts no longer occur if the insert into one of the materialized views is not possible because it has too many parts.
- Corrected the discrepancy in the event counters
Query
,SelectQuery
, andInsertQuery
. - Expressions like
tuple IN (SELECT tuple)
are allowed if the tuple types match. - A server with replicated tables can start even if you haven't configured ZooKeeper.
- When calculating the number of available CPU cores, limits on cgroups are now taken into account (Atri Sharma).
- Added chown for config directories in the systemd config file (Mikhail Shiryaev).
Build changes:
- The gcc8 compiler can be used for builds.
- Added the ability to build llvm from submodule.
- The version of the librdkafka library has been updated to v0.11.4.
- Added the ability to use the system libcpuid library. The library version has been updated to 0.4.0.
- Fixed the build using the vectorclass library (Babacar Diassé).
- Cmake now generates files for ninja by default (like when using
-G Ninja
). - Added the ability to use the libtinfo library instead of libtermcap (Georgy Kondratiev).
- Fixed a header file conflict in Fedora Rawhide (#2520).
Backward incompatible changes:
- Removed escaping in
Vertical
andPretty*
formats and deleted theVerticalRaw
format. - If servers with version 1.1.54388 (or newer) and servers with an older version are used simultaneously in a distributed query and the query has the
cast(x, 'Type')
expression without theAS
keyword and doesn't have the wordcast
in uppercase, an exception will be thrown with a message likeNot found column cast(0, 'UInt8') in block
. Solution: Update the server on the entire cluster.
ClickHouse release 1.1.54385, 2018-06-01
Bug fixes:
- Fixed an error that in some cases caused ZooKeeper operations to block.
ClickHouse release 1.1.54383, 2018-05-22
Bug fixes:
- Fixed a slowdown of replication queue if a table has many replicas.
ClickHouse release 1.1.54381, 2018-05-14
Bug fixes:
- Fixed a nodes leak in ZooKeeper when ClickHouse loses connection to ZooKeeper server.
ClickHouse release 1.1.54380, 2018-04-21
New features:
- Added the table function
file(path, format, structure)
. An example reading bytes from/dev/urandom
:ln -s /dev/urandom /var/lib/clickhouse/user_files/random``clickhouse-client -q "SELECT * FROM file('random', 'RowBinary', 'd UInt8') LIMIT 10"
.
Improvements:
- Subqueries can be wrapped in
()
brackets to enhance query readability. For example:(SELECT 1) UNION ALL (SELECT 1)
. - Simple
SELECT
queries from thesystem.processes
table are not included in themax_concurrent_queries
limit.
Bug fixes:
- Fixed incorrect behavior of the
IN
operator when select fromMATERIALIZED VIEW
. - Fixed incorrect filtering by partition index in expressions like
partition_key_column IN (...)
. - Fixed inability to execute
OPTIMIZE
query on non-leader replica ifREANAME
was performed on the table. - Fixed the authorization error when executing
OPTIMIZE
orALTER
queries on a non-leader replica. - Fixed freezing of
KILL QUERY
. - Fixed an error in ZooKeeper client library which led to loss of watches, freezing of distributed DDL queue, and slowdowns in the replication queue if a non-empty
chroot
prefix is used in the ZooKeeper configuration.
Backward incompatible changes:
- Removed support for expressions like
(a, b) IN (SELECT (a, b))
(you can use the equivalent expression(a, b) IN (SELECT a, b)
). In previous releases, these expressions led to undeterminedWHERE
filtering or caused errors.
ClickHouse release 1.1.54378, 2018-04-16
New features:
- Logging level can be changed without restarting the server.
- Added the
SHOW CREATE DATABASE
query. - The
query_id
can be passed toclickhouse-client
(elBroom). - New setting:
max_network_bandwidth_for_all_users
. - Added support for
ALTER TABLE ... PARTITION ...
forMATERIALIZED VIEW
. - Added information about the size of data parts in uncompressed form in the system table.
- Server-to-server encryption support for distributed tables (
<secure>1</secure>
in the replica config in<remote_servers>
). - Configuration of the table level for the
ReplicatedMergeTree
family in order to minimize the amount of data stored in Zookeeper: :use_minimalistic_checksums_in_zookeeper = 1
- Configuration of the
clickhouse-client
prompt. By default, server names are now output to the prompt. The server's display name can be changed. It's also sent in theX-ClickHouse-Display-Name
HTTP header (Kirill Shvakov). - Multiple comma-separated
topics
can be specified for theKafka
engine (Tobias Adamson) - When a query is stopped by
KILL QUERY
orreplace_running_query
, the client receives theQuery was cancelled
exception instead of an incomplete result.
Improvements:
ALTER TABLE ... DROP/DETACH PARTITION
queries are run at the front of the replication queue.SELECT ... FINAL
andOPTIMIZE ... FINAL
can be used even when the table has a single data part.- A
query_log
table is recreated on the fly if it was deleted manually (Kirill Shvakov). - The
lengthUTF8
function runs faster (zhang2014). - Improved performance of synchronous inserts in
Distributed
tables (insert_distributed_sync = 1
) when there is a very large number of shards. - The server accepts the
send_timeout
andreceive_timeout
settings from the client and applies them when connecting to the client (they are applied in reverse order: the server socket'ssend_timeout
is set to thereceive_timeout
value received from the client, and vice versa). - More robust crash recovery for asynchronous insertion into
Distributed
tables. - The return type of the
countEqual
function changed fromUInt32
toUInt64
(谢磊).
Bug fixes:
- Fixed an error with
IN
when the left side of the expression isNullable
. - Correct results are now returned when using tuples with
IN
when some of the tuple components are in the table index. - The
max_execution_time
limit now works correctly with distributed queries. - Fixed errors when calculating the size of composite columns in the
system.columns
table. - Fixed an error when creating a temporary table
CREATE TEMPORARY TABLE IF NOT EXISTS.
- Fixed errors in
StorageKafka
(##2075) - Fixed server crashes from invalid arguments of certain aggregate functions.
- Fixed the error that prevented the
DETACH DATABASE
query from stopping background tasks forReplicatedMergeTree
tables. Too many parts
state is less likely to happen when inserting into aggregated materialized views (##2084).- Corrected recursive handling of substitutions in the config if a substitution must be followed by another substitution on the same level.
- Corrected the syntax in the metadata file when creating a
VIEW
that uses a query withUNION ALL
. SummingMergeTree
now works correctly for summation of nested data structures with a composite key.- Fixed the possibility of a race condition when choosing the leader for
ReplicatedMergeTree
tables.
Build changes:
- The build supports
ninja
instead ofmake
and usesninja
by default for building releases. - Renamed packages:
clickhouse-server-base
inclickhouse-common-static
;clickhouse-server-common
inclickhouse-server
;clickhouse-common-dbg
inclickhouse-common-static-dbg
. To install, useclickhouse-server clickhouse-client
. Packages with the old names will still load in the repositories for backward compatibility.
Backward incompatible changes:
- Removed the special interpretation of an IN expression if an array is specified on the left side. Previously, the expression
arr IN (set)
was interpreted as "at least onearr
element belongs to theset
". To get the same behavior in the new version, writearrayExists(x -> x IN (set), arr)
. - Disabled the incorrect use of the socket option
SO_REUSEPORT
, which was incorrectly enabled by default in the Poco library. Note that on Linux there is no longer any reason to simultaneously specify the addresses::
and0.0.0.0
for listen – use just::
, which allows listening to the connection both over IPv4 and IPv6 (with the default kernel config settings). You can also revert to the behavior from previous versions by specifying<listen_reuse_port>1</listen_reuse_port>
in the config.
ClickHouse release 1.1.54370, 2018-03-16
New features:
- Added the
system.macros
table and auto updating of macros when the config file is changed. - Added the
SYSTEM RELOAD CONFIG
query. - Added the
maxIntersections(left_col, right_col)
aggregate function, which returns the maximum number of simultaneously intersecting intervals[left; right]
. ThemaxIntersectionsPosition(left, right)
function returns the beginning of the "maximum" interval. (Michael Furmur).
Improvements:
- When inserting data in a
Replicated
table, fewer requests are made toZooKeeper
(and most of the user-level errors have disappeared from theZooKeeper
log). - Added the ability to create aliases for data sets. Example:
WITH (1, 2, 3) AS set SELECT number IN set FROM system.numbers LIMIT 10
.
Bug fixes:
- Fixed the
Illegal PREWHERE
error when reading from Merge tables forDistributed
tables. - Added fixes that allow you to start clickhouse-server in IPv4-only Docker containers.
- Fixed a race condition when reading from system
system.parts_columns tables.
- Removed double buffering during a synchronous insert to a
Distributed
table, which could have caused the connection to timeout. - Fixed a bug that caused excessively long waits for an unavailable replica before beginning a
SELECT
query. - Fixed incorrect dates in the
system.parts
table. - Fixed a bug that made it impossible to insert data in a
Replicated
table ifchroot
was non-empty in the configuration of theZooKeeper
cluster. - Fixed the vertical merging algorithm for an empty
ORDER BY
table. - Restored the ability to use dictionaries in queries to remote tables, even if these dictionaries are not present on the requestor server. This functionality was lost in release 1.1.54362.
- Restored the behavior for queries like
SELECT * FROM remote('server2', default.table) WHERE col IN (SELECT col2 FROM default.table)
when the right side of theIN
should use a remotedefault.table
instead of a local one. This behavior was broken in version 1.1.54358. - Removed extraneous error-level logging of
Not found column ... in block
.
Clickhouse Release 1.1.54362, 2018-03-11
New features:
- Aggregation without
GROUP BY
for an empty set (such asSELECT count(*) FROM table WHERE 0
) now returns a result with one row with null values for aggregate functions, in compliance with the SQL standard. To restore the old behavior (return an empty result), setempty_result_for_aggregation_by_empty_set
to 1. - Added type conversion for
UNION ALL
. Different alias names are allowed inSELECT
positions inUNION ALL
, in compliance with the SQL standard. - Arbitrary expressions are supported in
LIMIT BY
clauses. Previously, it was only possible to use columns resulting fromSELECT
. - An index of
MergeTree
tables is used whenIN
is applied to a tuple of expressions from the columns of the primary key. Example:WHERE (UserID, EventDate) IN ((123, '2000-01-01'), ...)
(Anastasiya Tsarkova). - Added the
clickhouse-copier
tool for copying between clusters and resharding data (beta). - Added consistent hashing functions:
yandexConsistentHash
,jumpConsistentHash
,sumburConsistentHash
. They can be used as a sharding key in order to reduce the amount of network traffic during subsequent reshardings. - Added functions:
arrayAny
,arrayAll
,hasAny
,hasAll
,arrayIntersect
,arrayResize
. - Added the
arrayCumSum
function (Javi Santana). - Added the
parseDateTimeBestEffort
,parseDateTimeBestEffortOrZero
, andparseDateTimeBestEffortOrNull
functions to read the DateTime from a string containing text in a wide variety of possible formats. - Data can be partially reloaded from external dictionaries during updating (load just the records in which the value of the specified field greater than in the previous download) (Arsen Hakobyan).
- Added the
cluster
table function. Example:cluster(cluster_name, db, table)
. Theremote
table function can accept the cluster name as the first argument, if it is specified as an identifier. - The
remote
andcluster
table functions can be used inINSERT
requests. - Added the
create_table_query
andengine_full
virtual columns to thesystem.tables
table . Themetadata_modification_time
column is virtual. - Added the
data_path
andmetadata_path
columns tosystem.tables
andsystem.databases
tables, and added thepath
column to thesystem.parts
andsystem.parts_columns
tables. - Added additional information about merges in the
system.part_log
table. - An arbitrary partitioning key can be used for the
system.query_log
table (Kirill Shvakov). - The
SHOW TABLES
query now also shows temporary tables. Added temporary tables and theis_temporary
column tosystem.tables
(zhang2014). - Added
DROP TEMPORARY TABLE
andEXISTS TEMPORARY TABLE
queries (zhang2014). - Support for
SHOW CREATE TABLE
for temporary tables (zhang2014). - Added the
system_profile
configuration parameter for the settings used by internal processes. - Support for loading
object_id
as an attribute inMongoDB
dictionaries (Pavel Litvinenko). - Reading
null
as the default value when loading data for an external dictionary with theMongoDB
source (Pavel Litvinenko). - Reading
DateTime
values in theValues
format from a Unix timestamp without single quotes. - Failover is supported in
remote
table functions for cases when some of the replicas are missing the requested table. - Configuration settings can be overridden in the command line when you run
clickhouse-server
. Example:clickhouse-server -- --logger.level=information
. - Implemented the
empty
function from aFixedString
argument: the function returns 1 if the string consists entirely of null bytes (zhang2014). - Added the
listen_try
configuration parameter for listening to at least one of the listen addresses without quitting, if some of the addresses can't be listened to (useful for systems with disabled support for IPv4 or IPv6). - Added the
VersionedCollapsingMergeTree
table engine. - Support for rows and arbitrary numeric types for the
library
dictionary source. MergeTree
tables can be used without a primary key (you need to specifyORDER BY tuple()
).- A
Nullable
type can beCAST
to a non-Nullable
type if the argument is notNULL
. RENAME TABLE
can be performed forVIEW
.- Added the
throwIf
function. - Added the
odbc_default_field_size
option, which allows you to extend the maximum size of the value loaded from an ODBC source (by default, it is 1024). - The
system.processes
table andSHOW PROCESSLIST
now have theis_cancelled
andpeak_memory_usage
columns.
Improvements:
- Limits and quotas on the result are no longer applied to intermediate data for
INSERT SELECT
queries or forSELECT
subqueries. - Fewer false triggers of
force_restore_data
when checking the status ofReplicated
tables when the server starts. - Added the
allow_distributed_ddl
option. - Nondeterministic functions are not allowed in expressions for
MergeTree
table keys. - Files with substitutions from
config.d
directories are loaded in alphabetical order. - Improved performance of the
arrayElement
function in the case of a constant multidimensional array with an empty array as one of the elements. Example:[[1], []][x]
. - The server starts faster now when using configuration files with very large substitutions (for instance, very large lists of IP networks).
- When running a query, table valued functions run once. Previously,
remote
andmysql
table valued functions performed the same query twice to retrieve the table structure from a remote server. - The
MkDocs
documentation generator is used. - When you try to delete a table column that
DEFAULT
/MATERIALIZED
expressions of other columns depend on, an exception is thrown (zhang2014). - Added the ability to parse an empty line in text formats as the number 0 for
Float
data types. This feature was previously available but was lost in release 1.1.54342. Enum
values can be used inmin
,max
,sum
and some other functions. In these cases, it uses the corresponding numeric values. This feature was previously available but was lost in the release 1.1.54337.- Added
max_expanded_ast_elements
to restrict the size of the AST after recursively expanding aliases.
Bug fixes:
- Fixed cases when unnecessary columns were removed from subqueries in error, or not removed from subqueries containing
UNION ALL
. - Fixed a bug in merges for
ReplacingMergeTree
tables. - Fixed synchronous insertions in
Distributed
tables (insert_distributed_sync = 1
). - Fixed segfault for certain uses of
FULL
andRIGHT JOIN
with duplicate columns in subqueries. - Fixed segfault for certain uses of
replace_running_query
andKILL QUERY
. - Fixed the order of the
source
andlast_exception
columns in thesystem.dictionaries
table. - Fixed a bug when the
DROP DATABASE
query did not delete the file with metadata. - Fixed the
DROP DATABASE
query forDictionary
databases. - Fixed the low precision of
uniqHLL12
anduniqCombined
functions for cardinalities greater than 100 million items (Alex Bocharov). - Fixed the calculation of implicit default values when necessary to simultaneously calculate default explicit expressions in
INSERT
queries (zhang2014). - Fixed a rare case when a query to a
MergeTree
table couldn't finish (chenxing-xc). - Fixed a crash that occurred when running a
CHECK
query forDistributed
tables if all shards are local (chenxing.xc). - Fixed a slight performance regression with functions that use regular expressions.
- Fixed a performance regression when creating multidimensional arrays from complex expressions.
- Fixed a bug that could cause an extra
FORMAT
section to appear in an.sql
file with metadata. - Fixed a bug that caused the
max_table_size_to_drop
limit to apply when trying to delete aMATERIALIZED VIEW
looking at an explicitly specified table. - Fixed incompatibility with old clients (old clients were sometimes sent data with the
DateTime('timezone')
type, which they do not understand). - Fixed a bug when reading
Nested
column elements of structures that were added usingALTER
but that are empty for the old partitions, when the conditions for these columns moved toPREWHERE
. - Fixed a bug when filtering tables by virtual
_table
columns in queries toMerge
tables. - Fixed a bug when using
ALIAS
columns inDistributed
tables. - Fixed a bug that made dynamic compilation impossible for queries with aggregate functions from the
quantile
family. - Fixed a race condition in the query execution pipeline that occurred in very rare cases when using
Merge
tables with a large number of tables, and when usingGLOBAL
subqueries. - Fixed a crash when passing arrays of different sizes to an
arrayReduce
function when using aggregate functions from multiple arguments. - Prohibited the use of queries with
UNION ALL
in aMATERIALIZED VIEW
. - Fixed an error during initialization of the
part_log
system table when the server starts (by default,part_log
is disabled).
Backward incompatible changes:
- Removed the
distributed_ddl_allow_replicated_alter
option. This behavior is enabled by default. - Removed the
strict_insert_defaults
setting. If you were using this functionality, write toclickhouse-feedback@yandex-team.com
. - Removed the
UnsortedMergeTree
engine.
Clickhouse Release 1.1.54343, 2018-02-05
- Added macros support for defining cluster names in distributed DDL queries and constructors of Distributed tables:
CREATE TABLE distr ON CLUSTER '{cluster}' (...) ENGINE = Distributed('{cluster}', 'db', 'table')
. - Now queries like
SELECT ... FROM table WHERE expr IN (subquery)
are processed using thetable
index. - Improved processing of duplicates when inserting to Replicated tables, so they no longer slow down execution of the replication queue.
Clickhouse Release 1.1.54342, 2018-01-22
This release contains bug fixes for the previous release 1.1.54337:
- Fixed a regression in 1.1.54337: if the default user has readonly access, then the server refuses to start up with the message
Cannot create database in readonly mode
. - Fixed a regression in 1.1.54337: on systems with systemd, logs are always written to syslog regardless of the configuration; the watchdog script still uses init.d.
- Fixed a regression in 1.1.54337: wrong default configuration in the Docker image.
- Fixed nondeterministic behavior of GraphiteMergeTree (you can see it in log messages
Data after merge is not byte-identical to the data on another replicas
). - Fixed a bug that may lead to inconsistent merges after OPTIMIZE query to Replicated tables (you may see it in log messages
Part ... intersects the previous part
). - Buffer tables now work correctly when MATERIALIZED columns are present in the destination table (by zhang2014).
- Fixed a bug in implementation of NULL.
Clickhouse Release 1.1.54337, 2018-01-18
New features:
- Added support for storage of multi-dimensional arrays and tuples (
Tuple
data type) in tables. - Support for table functions for
DESCRIBE
andINSERT
queries. Added support for subqueries inDESCRIBE
. Examples:DESC TABLE remote('host', default.hits)
;DESC TABLE (SELECT 1)
;INSERT INTO TABLE FUNCTION remote('host', default.hits)
. Support forINSERT INTO TABLE
in addition toINSERT INTO
. - Improved support for time zones. The
DateTime
data type can be annotated with the timezone that is used for parsing and formatting in text formats. Example:DateTime('Europe/Moscow')
. When timezones are specified in functions forDateTime
arguments, the return type will track the timezone, and the value will be displayed as expected. - Added the functions
toTimeZone
,timeDiff
,toQuarter
,toRelativeQuarterNum
. ThetoRelativeHour
/Minute
/Second
functions can take a value of typeDate
as an argument. Thenow
function name is case-sensitive. - Added the
toStartOfFifteenMinutes
function (Kirill Shvakov). - Added the
clickhouse format
tool for formatting queries. - Added the
format_schema_path
configuration parameter (Marek Vavruşa). It is used for specifying a schema inCap'n Proto
format. Schema files can be located only in the specified directory. - Added support for config substitutions (
incl
andconf.d
) for configuration of external dictionaries and models (Pavel Yakunin). - Added a column with documentation for the
system.settings
table (Kirill Shvakov). - Added the
system.parts_columns
table with information about column sizes in each data part ofMergeTree
tables. - Added the
system.models
table with information about loadedCatBoost
machine learning models. - Added the
mysql
andodbc
table function and correspondingMySQL
andODBC
table engines for accessing remote databases. This functionality is in the beta stage. - Added the possibility to pass an argument of type
AggregateFunction
for thegroupArray
aggregate function (so you can create an array of states of some aggregate function). - Removed restrictions on various combinations of aggregate function combinators. For example, you can use
avgForEachIf
as well asavgIfForEach
aggregate functions, which have different behaviors. - The
-ForEach
aggregate function combinator is extended for the case of aggregate functions of multiple arguments. - Added support for aggregate functions of
Nullable
arguments even for cases when the function returns a non-Nullable
result (added with the contribution of Silviu Caragea). Example:groupArray
,groupUniqArray
,topK
. - Added the
max_client_network_bandwidth
forclickhouse-client
(Kirill Shvakov). - Users with the
readonly = 2
setting are allowed to work with TEMPORARY tables (CREATE, DROP, INSERT...) (Kirill Shvakov). - Added support for using multiple consumers with the
Kafka
engine. Extended configuration options forKafka
(Marek Vavruša). - Added the
intExp3
andintExp4
functions. - Added the
sumKahan
aggregate function. - Added the to * Number* OrNull functions, where * Number* is a numeric type.
- Added support for
WITH
clauses for anINSERT SELECT
query (author: zhang2014). - Added settings:
http_connection_timeout
,http_send_timeout
,http_receive_timeout
. In particular, these settings are used for downloading data parts for replication. Changing these settings allows for faster failover if the network is overloaded. - Added support for
ALTER
for tables of typeNull
(Anastasiya Tsarkova). - The
reinterpretAsString
function is extended for all data types that are stored contiguously in memory. - Added the
--silent
option for theclickhouse-local
tool. It suppresses printing query execution info in stderr. - Added support for reading values of type
Date
from text in a format where the month and/or day of the month is specified using a single digit instead of two digits (Amos Bird).
Performance optimizations:
- Improved performance of aggregate functions
min
,max
,any
,anyLast
,anyHeavy
,argMin
,argMax
from string arguments. - Improved performance of the functions
isInfinite
,isFinite
,isNaN
,roundToExp2
. - Improved performance of parsing and formatting
Date
andDateTime
type values in text format. - Improved performance and precision of parsing floating point numbers.
- Lowered memory usage for
JOIN
in the case when the left and right parts have columns with identical names that are not contained inUSING
. - Improved performance of aggregate functions
varSamp
,varPop
,stddevSamp
,stddevPop
,covarSamp
,covarPop
,corr
by reducing computational stability. The old functions are available under the namesvarSampStable
,varPopStable
,stddevSampStable
,stddevPopStable
,covarSampStable
,covarPopStable
,corrStable
.
Bug fixes:
- Fixed data deduplication after running a
DROP
orDETACH PARTITION
query. In the previous version, dropping a partition and inserting the same data again was not working because inserted blocks were considered duplicates. - Fixed a bug that could lead to incorrect interpretation of the
WHERE
clause forCREATE MATERIALIZED VIEW
queries withPOPULATE
. - Fixed a bug in using the
root_path
parameter in thezookeeper_servers
configuration. - Fixed unexpected results of passing the
Date
argument totoStartOfDay
. - Fixed the
addMonths
andsubtractMonths
functions and the arithmetic forINTERVAL n MONTH
in cases when the result has the previous year. - Added missing support for the
UUID
data type forDISTINCT
,JOIN
, anduniq
aggregate functions and external dictionaries (Evgeniy Ivanov). Support forUUID
is still incomplete. - Fixed
SummingMergeTree
behavior in cases when the rows summed to zero. - Various fixes for the
Kafka
engine (Marek Vavruša). - Fixed incorrect behavior of the
Join
table engine (Amos Bird). - Fixed incorrect allocator behavior under FreeBSD and OS X.
- The
extractAll
function now supports empty matches. - Fixed an error that blocked usage of
libressl
instead ofopenssl
. - Fixed the
CREATE TABLE AS SELECT
query from temporary tables. - Fixed non-atomicity of updating the replication queue. This could lead to replicas being out of sync until the server restarts.
- Fixed possible overflow in
gcd
,lcm
andmodulo
(%
operator) (Maks Skorokhod). -preprocessed
files are now created after changingumask
(umask
can be changed in the config).- Fixed a bug in the background check of parts (
MergeTreePartChecker
) when using a custom partition key. - Fixed parsing of tuples (values of the
Tuple
data type) in text formats. - Improved error messages about incompatible types passed to
multiIf
,array
and some other functions. - Redesigned support for
Nullable
types. Fixed bugs that may lead to a server crash. Fixed almost all other bugs related toNULL
support: incorrect type conversions in INSERT SELECT, insufficient support for Nullable in HAVING and PREWHERE,join_use_nulls
mode, Nullable types as arguments ofOR
operator, etc. - Fixed various bugs related to internal semantics of data types. Examples: unnecessary summing of
Enum
type fields inSummingMergeTree
; alignment ofEnum
types inPretty
formats, etc. - Stricter checks for allowed combinations of composite columns.
- Fixed the overflow when specifying a very large parameter for the
FixedString
data type. - Fixed a bug in the
topK
aggregate function in a generic case. - Added the missing check for equality of array sizes in arguments of n-ary variants of aggregate functions with an
-Array
combinator. - Fixed a bug in
--pager
forclickhouse-client
(author: ks1322). - Fixed the precision of the
exp10
function. - Fixed the behavior of the
visitParamExtract
function for better compliance with documentation. - Fixed the crash when incorrect data types are specified.
- Fixed the behavior of
DISTINCT
in the case when all columns are constants. - Fixed query formatting in the case of using the
tupleElement
function with a complex constant expression as the tuple element index. - Fixed a bug in
Dictionary
tables forrange_hashed
dictionaries. - Fixed a bug that leads to excessive rows in the result of
FULL
andRIGHT JOIN
(Amos Bird). - Fixed a server crash when creating and removing temporary files in
config.d
directories during config reload. - Fixed the
SYSTEM DROP DNS CACHE
query: the cache was flushed but addresses of cluster nodes were not updated. - Fixed the behavior of
MATERIALIZED VIEW
after executingDETACH TABLE
for the table under the view (Marek Vavruša).
Build improvements:
- The
pbuilder
tool is used for builds. The build process is almost completely independent of the build host environment. - A single build is used for different OS versions. Packages and binaries have been made compatible with a wide range of Linux systems.
- Added the
clickhouse-test
package. It can be used to run functional tests. - The source tarball can now be published to the repository. It can be used to reproduce the build without using GitHub.
- Added limited integration with Travis CI. Due to limits on build time in Travis, only the debug build is tested and a limited subset of tests are run.
- Added support for
Cap'n'Proto
in the default build. - Changed the format of documentation sources from
Restricted Text
toMarkdown
. - Added support for
systemd
(Vladimir Smirnov). It is disabled by default due to incompatibility with some OS images and can be enabled manually. - For dynamic code generation,
clang
andlld
are embedded into theclickhouse
binary. They can also be invoked asclickhouse clang
andclickhouse lld
. - Removed usage of GNU extensions from the code. Enabled the
-Wextra
option. When building withclang
the default islibc++
instead oflibstdc++
. - Extracted
clickhouse_parsers
andclickhouse_common_io
libraries to speed up builds of various tools.
Backward incompatible changes:
- The format for marks in
Log
type tables that containNullable
columns was changed in a backward incompatible way. If you have these tables, you should convert them to theTinyLog
type before starting up the new server version. To do this, replaceENGINE = Log
withENGINE = TinyLog
in the corresponding.sql
file in themetadata
directory. If your table doesn't haveNullable
columns or if the type of your table is notLog
, then you don't need to do anything. - Removed the
experimental_allow_extended_storage_definition_syntax
setting. Now this feature is enabled by default. - The
runningIncome
function was renamed torunningDifferenceStartingWithFirstvalue
to avoid confusion. - Removed the
FROM ARRAY JOIN arr
syntax when ARRAY JOIN is specified directly after FROM with no table (Amos Bird). - Removed the
BlockTabSeparated
format that was used solely for demonstration purposes. - Changed the state format for aggregate functions
varSamp
,varPop
,stddevSamp
,stddevPop
,covarSamp
,covarPop
,corr
. If you have stored states of these aggregate functions in tables (using theAggregateFunction
data type or materialized views with corresponding states), please write to clickhouse-feedback@yandex-team.com. - In previous server versions there was an undocumented feature: if an aggregate function depends on parameters, you can still specify it without parameters in the AggregateFunction data type. Example:
AggregateFunction(quantiles, UInt64)
instead ofAggregateFunction(quantiles(0.5, 0.9), UInt64)
. This feature was lost. Although it was undocumented, we plan to support it again in future releases. - Enum data types cannot be used in min/max aggregate functions. This ability will be returned in the next release.
Please note when upgrading:
- When doing a rolling update on a cluster, at the point when some of the replicas are running the old version of ClickHouse and some are running the new version, replication is temporarily stopped and the message
unknown parameter 'shard'
appears in the log. Replication will continue after all replicas of the cluster are updated. - If different versions of ClickHouse are running on the cluster servers, it is possible that distributed queries using the following functions will have incorrect results:
varSamp
,varPop
,stddevSamp
,stddevPop
,covarSamp
,covarPop
,corr
. You should update all cluster nodes.
ClickHouse release 1.1.54327, 2017-12-21
This release contains bug fixes for the previous release 1.1.54318:
- Fixed bug with possible race condition in replication that could lead to data loss. This issue affects versions 1.1.54310 and 1.1.54318. If you use one of these versions with Replicated tables, the update is strongly recommended. This issue shows in logs in Warning messages like
Part ... from own log doesn't exist.
The issue is relevant even if you don't see these messages in logs.
ClickHouse release 1.1.54318, 2017-11-30
This release contains bug fixes for the previous release 1.1.54310:
- Fixed incorrect row deletions during merges in the SummingMergeTree engine
- Fixed a memory leak in unreplicated MergeTree engines
- Fixed performance degradation with frequent inserts in MergeTree engines
- Fixed an issue that was causing the replication queue to stop running
- Fixed rotation and archiving of server logs
ClickHouse release 1.1.54310, 2017-11-01
New features:
- Custom partitioning key for the MergeTree family of table engines.
- Kafka table engine.
- Added support for loading CatBoost models and applying them to data stored in ClickHouse.
- Added support for time zones with non-integer offsets from UTC.
- Added support for arithmetic operations with time intervals.
- The range of values for the Date and DateTime types is extended to the year 2105.
- Added the
CREATE MATERIALIZED VIEW x TO y
query (specifies an existing table for storing the data of a materialized view). - Added the
ATTACH TABLE
query without arguments. - The processing logic for Nested columns with names ending in -Map in a SummingMergeTree table was extracted to the sumMap aggregate function. You can now specify such columns explicitly.
- Max size of the IP trie dictionary is increased to 128M entries.
- Added the getSizeOfEnumType function.
- Added the sumWithOverflow aggregate function.
- Added support for the Cap'n Proto input format.
- You can now customize compression level when using the zstd algorithm.
Backward incompatible changes:
- Creation of temporary tables with an engine other than Memory is not allowed.
- Explicit creation of tables with the View or MaterializedView engine is not allowed.
- During table creation, a new check verifies that the sampling key expression is included in the primary key.
Bug fixes:
- Fixed hangups when synchronously inserting into a Distributed table.
- Fixed nonatomic adding and removing of parts in Replicated tables.
- Data inserted into a materialized view is not subjected to unnecessary deduplication.
- Executing a query to a Distributed table for which the local replica is lagging and remote replicas are unavailable does not result in an error anymore.
- Users don't need access permissions to the
default
database to create temporary tables anymore. - Fixed crashing when specifying the Array type without arguments.
- Fixed hangups when the disk volume containing server logs is full.
- Fixed an overflow in the toRelativeWeekNum function for the first week of the Unix epoch.
Build improvements:
- Several third-party libraries (notably Poco) were updated and converted to git submodules.
ClickHouse release 1.1.54304, 2017-10-19
New features:
- TLS support in the native protocol (to enable, set
tcp_ssl_port
inconfig.xml
).
Bug fixes:
ALTER
for replicated tables now tries to start running as soon as possible.- Fixed crashing when reading data with the setting
preferred_block_size_bytes=0.
- Fixed crashes of
clickhouse-client
when pressingPage Down
- Correct interpretation of certain complex queries with
GLOBAL IN
andUNION ALL
FREEZE PARTITION
always works atomically now.- Empty POST requests now return a response with code 411.
- Fixed interpretation errors for expressions like
CAST(1 AS Nullable(UInt8)).
- Fixed an error when reading
Array(Nullable(String))
columns fromMergeTree
tables. - Fixed crashing when parsing queries like
SELECT dummy AS dummy, dummy AS b
- Users are updated correctly with invalid
users.xml
- Correct handling when an executable dictionary returns a non-zero response code.
ClickHouse release 1.1.54292, 2017-09-20
New features:
- Added the
pointInPolygon
function for working with coordinates on a coordinate plane. - Added the
sumMap
aggregate function for calculating the sum of arrays, similar toSummingMergeTree
. - Added the
trunc
function. Improved performance of the rounding functions (round
,floor
,ceil
,roundToExp2
) and corrected the logic of how they work. Changed the logic of theroundToExp2
function for fractions and negative numbers. - The ClickHouse executable file is now less dependent on the libc version. The same ClickHouse executable file can run on a wide variety of Linux systems. There is still a dependency when using compiled queries (with the setting
compile = 1
, which is not used by default). - Reduced the time needed for dynamic compilation of queries.
Bug fixes:
- Fixed an error that sometimes produced
part ... intersects previous part
messages and weakened replica consistency. - Fixed an error that caused the server to lock up if ZooKeeper was unavailable during shutdown.
- Removed excessive logging when restoring replicas.
- Fixed an error in the UNION ALL implementation.
- Fixed an error in the concat function that occurred if the first column in a block has the Array type.
- Progress is now displayed correctly in the system.merges table.
ClickHouse release 1.1.54289, 2017-09-13
New features:
SYSTEM
queries for server administration:SYSTEM RELOAD DICTIONARY
,SYSTEM RELOAD DICTIONARIES
,SYSTEM DROP DNS CACHE
,SYSTEM SHUTDOWN
,SYSTEM KILL
.- Added functions for working with arrays:
concat
,arraySlice
,arrayPushBack
,arrayPushFront
,arrayPopBack
,arrayPopFront
. - Added
root
andidentity
parameters for the ZooKeeper configuration. This allows you to isolate individual users on the same ZooKeeper cluster. - Added aggregate functions
groupBitAnd
,groupBitOr
, andgroupBitXor
(for compatibility, they are also available under the namesBIT_AND
,BIT_OR
, andBIT_XOR
). - External dictionaries can be loaded from MySQL by specifying a socket in the filesystem.
- External dictionaries can be loaded from MySQL over SSL (
ssl_cert
,ssl_key
,ssl_ca
parameters). - Added the
max_network_bandwidth_for_user
setting to restrict the overall bandwidth use for queries per user. - Support for
DROP TABLE
for temporary tables. - Support for reading
DateTime
values in Unix timestamp format from theCSV
andJSONEachRow
formats. - Lagging replicas in distributed queries are now excluded by default (the default threshold is 5 minutes).
- FIFO locking is used during ALTER: an ALTER query isn't blocked indefinitely for continuously running queries.
- Option to set
umask
in the config file. - Improved performance for queries with
DISTINCT
.
Bug fixes:
- Improved the process for deleting old nodes in ZooKeeper. Previously, old nodes sometimes didn't get deleted if there were very frequent inserts, which caused the server to be slow to shut down, among other things.
- Fixed randomization when choosing hosts for the connection to ZooKeeper.
- Fixed the exclusion of lagging replicas in distributed queries if the replica is localhost.
- Fixed an error where a data part in a
ReplicatedMergeTree
table could be broken after runningALTER MODIFY
on an element in aNested
structure. - Fixed an error that could cause SELECT queries to "hang".
- Improvements to distributed DDL queries.
- Fixed the query
CREATE TABLE ... AS <materialized view>
. - Resolved the deadlock in the
ALTER ... CLEAR COLUMN IN PARTITION
query forBuffer
tables. - Fixed the invalid default value for
Enum
s (0 instead of the minimum) when using theJSONEachRow
andTSKV
formats. - Resolved the appearance of zombie processes when using a dictionary with an
executable
source. - Fixed segfault for the HEAD query.
Improved workflow for developing and assembling ClickHouse:
- You can use
pbuilder
to build ClickHouse. - You can use
libc++
instead oflibstdc++
for builds on Linux. - Added instructions for using static code analysis tools:
Coverage
,clang-tidy
,cppcheck
.
Please note when upgrading:
- There is now a higher default value for the MergeTree setting
max_bytes_to_merge_at_max_space_in_pool
(the maximum total size of data parts to merge, in bytes): it has increased from 100 GiB to 150 GiB. This might result in large merges running after the server upgrade, which could cause an increased load on the disk subsystem. If the free space available on the server is less than twice the total amount of the merges that are running, this will cause all other merges to stop running, including merges of small data parts. As a result, INSERT requests will fail with the message "Merges are processing significantly slower than inserts." Use theSELECT * FROM system.merges
request to monitor the situation. You can also check theDiskSpaceReservedForMerge
metric in thesystem.metrics
table, or in Graphite. You don't need to do anything to fix this, since the issue will resolve itself once the large merges finish. If you find this unacceptable, you can restore the previous value for themax_bytes_to_merge_at_max_space_in_pool
setting. To do this, go to the <merge_tree> section in config.xml, set<merge_tree>``<max_bytes_to_merge_at_max_space_in_pool>107374182400</max_bytes_to_merge_at_max_space_in_pool>
and restart the server.
ClickHouse release 1.1.54284, 2017-08-29
- This is a bugfix release for the previous 1.1.54282 release. It fixes leaks in the parts directory in ZooKeeper.
ClickHouse release 1.1.54282, 2017-08-23
This release contains bug fixes for the previous release 1.1.54276:
- Fixed
DB::Exception: Assertion violation: !_path.empty()
when inserting into a Distributed table. - Fixed parsing when inserting in RowBinary format if input data starts with';'.
- Errors during runtime compilation of certain aggregate functions (e.g.
groupArray()
).
Clickhouse Release 1.1.54276, 2017-08-16
New features:
- Added an optional WITH section for a SELECT query. Example query:
WITH 1+1 AS a SELECT a, a*a
- INSERT can be performed synchronously in a Distributed table: OK is returned only after all the data is saved on all the shards. This is activated by the setting insert_distributed_sync=1.
- Added the UUID data type for working with 16-byte identifiers.
- Added aliases of CHAR, FLOAT and other types for compatibility with the Tableau.
- Added the functions toYYYYMM, toYYYYMMDD, and toYYYYMMDDhhmmss for converting time into numbers.
- You can use IP addresses (together with the hostname) to identify servers for clustered DDL queries.
- Added support for non-constant arguments and negative offsets in the function
substring(str, pos, len).
- Added the max_size parameter for the
groupArray(max_size)(column)
aggregate function, and optimized its performance.
Main changes:
- Security improvements: all server files are created with 0640 permissions (can be changed via config parameter).
- Improved error messages for queries with invalid syntax.
- Significantly reduced memory consumption and improved performance when merging large sections of MergeTree data.
- Significantly increased the performance of data merges for the ReplacingMergeTree engine.
- Improved performance for asynchronous inserts from a Distributed table by combining multiple source inserts. To enable this functionality, use the setting distributed_directory_monitor_batch_inserts=1.
Backward incompatible changes:
- Changed the binary format of aggregate states of
groupArray(array_column)
functions for arrays.
Complete list of changes:
- Added the
output_format_json_quote_denormals
setting, which enables outputting nan and inf values in JSON format. - Optimized stream allocation when reading from a Distributed table.
- Settings can be configured in readonly mode if the value doesn't change.
- Added the ability to retrieve non-integer granules of the MergeTree engine in order to meet restrictions on the block size specified in the preferred_block_size_bytes setting. The purpose is to reduce the consumption of RAM and increase cache locality when processing queries from tables with large columns.
- Efficient use of indexes that contain expressions like
toStartOfHour(x)
for conditions liketoStartOfHour(x) op сonstexpr.
- Added new settings for MergeTree engines (the merge_tree section in config.xml):
- replicated_deduplication_window_seconds sets the number of seconds allowed for deduplicating inserts in Replicated tables.
- cleanup_delay_period sets how often to start cleanup to remove outdated data.
- replicated_can_become_leader can prevent a replica from becoming the leader (and assigning merges).
- Accelerated cleanup to remove outdated data from ZooKeeper.
- Multiple improvements and fixes for clustered DDL queries. Of particular interest is the new setting distributed_ddl_task_timeout, which limits the time to wait for a response from the servers in the cluster.
- Improved display of stack traces in the server logs.
- Added the "none" value for the compression method.
- You can use multiple dictionaries_config sections in config.xml.
- It is possible to connect to MySQL through a socket in the file system.
- The system.parts table has a new column with information about the size of marks, in bytes.
Bug fixes:
- Distributed tables using a Merge table now work correctly for a SELECT query with a condition on the
_table
field. - Fixed a rare race condition in ReplicatedMergeTree when checking data parts.
- Fixed possible freezing on "leader election" when starting a server.
- The max_replica_delay_for_distributed_queries setting was ignored when using a local replica of the data source. This has been fixed.
- Fixed incorrect behavior of
ALTER TABLE CLEAR COLUMN IN PARTITION
when attempting to clean a non-existing column. - Fixed an exception in the multiIf function when using empty arrays or strings.
- Fixed excessive memory allocations when deserializing Native format.
- Fixed incorrect auto-update of Trie dictionaries.
- Fixed an exception when running queries with a GROUP BY clause from a Merge table when using SAMPLE.
- Fixed a crash of GROUP BY when using distributed_aggregation_memory_efficient=1.
- Now you can specify the database.table in the right side of IN and JOIN.
- Too many threads were used for parallel aggregation. This has been fixed.
- Fixed how the "if" function works with FixedString arguments.
- SELECT worked incorrectly from a Distributed table for shards with a weight of 0. This has been fixed.
- Running
CREATE VIEW IF EXISTS no longer causes crashes.
- Fixed incorrect behavior when input_format_skip_unknown_fields=1 is set and there are negative numbers.
- Fixed an infinite loop in the
dictGetHierarchy()
function if there is some invalid data in the dictionary. - Fixed
Syntax error: unexpected (...)
errors when running distributed queries with subqueries in an IN or JOIN clause and Merge tables. - Fixed an incorrect interpretation of a SELECT query from Dictionary tables.
- Fixed the "Cannot mremap" error when using arrays in IN and JOIN clauses with more than 2 billion elements.
- Fixed the failover for dictionaries with MySQL as the source.
Improved workflow for developing and assembling ClickHouse:
- Builds can be assembled in Arcadia.
- You can use gcc 7 to compile ClickHouse.
- Parallel builds using ccache+distcc are faster now.
ClickHouse release 1.1.54245, 2017-07-04
New features:
- Distributed DDL (for example,
CREATE TABLE ON CLUSTER
) - The replicated request
ALTER TABLE CLEAR COLUMN IN PARTITION.
- The engine for Dictionary tables (access to dictionary data in the form of a table).
- Dictionary database engine (this type of database automatically has Dictionary tables available for all the connected external dictionaries).
- You can check for updates to the dictionary by sending a request to the source.
- Qualified column names
- Quoting identifiers using double quotation marks.
- Sessions in the HTTP interface.
- The OPTIMIZE query for a Replicated table can can run not only on the leader.
Backward incompatible changes:
- Removed SET GLOBAL.
Minor changes:
- Now after an alert is triggered, the log prints the full stack trace.
- Relaxed the verification of the number of damaged/extra data parts at startup (there were too many false positives).
Bug fixes:
- Fixed a bad connection "sticking" when inserting into a Distributed table.
- GLOBAL IN now works for a query from a Merge table that looks at a Distributed table.
- The incorrect number of cores was detected on a Google Compute Engine virtual machine. This has been fixed.
- Changes in how an executable source of cached external dictionaries works.
- Fixed the comparison of strings containing null characters.
- Fixed the comparison of Float32 primary key fields with constants.
- Previously, an incorrect estimate of the size of a field could lead to overly large allocations.
- Fixed a crash when querying a Nullable column added to a table using ALTER.
- Fixed a crash when sorting by a Nullable column, if the number of rows is less than LIMIT.
- Fixed an ORDER BY subquery consisting of only constant values.
- Previously, a Replicated table could remain in the invalid state after a failed DROP TABLE.
- Aliases for scalar subqueries with empty results are no longer lost.
- Now a query that used compilation does not fail with an error if the .so file gets damaged.