Merge branch 'master' into ast-table-identifier-2

docker/test/fasttest/Dockerfile

@@ -82,6 +82,7 @@ RUN ln -snf /usr/share/zoneinfo/$TZ /etc/localtime && echo $TZ > /etc/timezone
 
 ENV COMMIT_SHA=''
 ENV PULL_REQUEST_NUMBER=''
+ENV COPY_CLICKHOUSE_BINARY_TO_OUTPUT=0
 
 COPY run.sh /
 CMD ["/bin/bash", "/run.sh"]

docker/test/fasttest/run.sh

@@ -172,6 +172,9 @@ function build
 (
 cd "$FASTTEST_BUILD"
 time ninja clickhouse-bundle | ts '%Y-%m-%d %H:%M:%S' | tee "$FASTTEST_OUTPUT/build_log.txt"
+if [ "$COPY_CLICKHOUSE_BINARY_TO_OUTPUT" -eq "1" ]; then
+    cp programs/clickhouse "$FASTTEST_OUTPUT/clickhouse"
+fi
 ccache --show-stats ||:
 )
 }

docker/test/stateless/run.sh

@@ -17,14 +17,24 @@ service clickhouse-server start && sleep 5
 if grep -q -- "--use-skip-list" /usr/bin/clickhouse-test; then
     SKIP_LIST_OPT="--use-skip-list"
 fi
-# We can have several additional options so we path them as array because it's
-# more idiologically correct.
-read -ra ADDITIONAL_OPTIONS <<< "${ADDITIONAL_OPTIONS:-}"
 
 function run_tests()
 {
+    # We can have several additional options so we path them as array because it's
+    # more idiologically correct.
+    read -ra ADDITIONAL_OPTIONS <<< "${ADDITIONAL_OPTIONS:-}"
+
+    # Skip these tests, because they fail when we rerun them multiple times
+    if [ "$NUM_TRIES" -gt "1" ]; then
+        ADDITIONAL_OPTIONS+=('--skip')
+        ADDITIONAL_OPTIONS+=('00000_no_tests_to_skip')
+    fi
+
     for i in $(seq 1 $NUM_TRIES); do
-        clickhouse-test --testname --shard --zookeeper --hung-check --print-time "$SKIP_LIST_OPT" "${ADDITIONAL_OPTIONS[@]}" "$SKIP_TESTS_OPTION" 2>&1 | ts '%Y-%m-%d %H:%M:%S' | tee -a test_output/test_result.txt
+        clickhouse-test --testname --shard --zookeeper --hung-check --print-time "$SKIP_LIST_OPT" "${ADDITIONAL_OPTIONS[@]}" 2>&1 | ts '%Y-%m-%d %H:%M:%S' | tee -a test_output/test_result.txt
+        if [ ${PIPESTATUS[0]} -ne "0" ]; then
+            break;
+        fi
     done
 }
 

docs/en/commercial/cloud.md

@@ -18,4 +18,14 @@ toc_title: Cloud
 -   Encryption and isolation
 -   Automated maintenance
 
+## Altinity.Cloud {#altinity.cloud}
+
+[Altinity.Cloud](https://altinity.com/cloud-database/) is a fully managed ClickHouse-as-a-Service for the Amazon public cloud. 
+-   Fast deployment of ClickHouse clusters on Amazon resources
+-   Easy scale-out/scale-in as well as vertical scaling of nodes
+-   Isolated per-tenant VPCs with public endpoint or VPC peering
+-   Configurable storage types and volume configurations
+-   Cross-AZ scaling for performance and high availability
+-   Built-in monitoring and SQL query editor
+
 {## [Original article](https://clickhouse.tech/docs/en/commercial/cloud/) ##}

docs/en/faq/integration/json-import.md

@@ -30,4 +30,4 @@ Instead of inserting data manually, you might consider to use one of [client lib
 -   `input_format_import_nested_json` allows to insert nested JSON objects into columns of [Nested](../../sql-reference/data-types/nested-data-structures/nested.md) type.
 
 !!! note "Note"
-    Settings are specified as `GET` parameters for the HTTP interface or as additional command-line arguments prefixed with `--` for the CLI interface.
+    Settings are specified as `GET` parameters for the HTTP interface or as additional command-line arguments prefixed with `--` for the `CLI` interface.

docs/en/getting-started/example-datasets/amplab-benchmark.md

@@ -1,5 +1,5 @@
 ---
-toc_priority: 17
+toc_priority: 19
 toc_title: AMPLab Big Data Benchmark
 ---
 

docs/en/getting-started/example-datasets/criteo.md

@@ -1,5 +1,5 @@
 ---
-toc_priority: 19
+toc_priority: 18
 toc_title: Terabyte Click Logs from Criteo
 ---
 

docs/en/getting-started/example-datasets/index.md

@@ -1,6 +1,6 @@
 ---
 toc_folder_title: Example Datasets
-toc_priority: 15
+toc_priority: 14
 toc_title: Introduction
 ---
 

docs/en/getting-started/example-datasets/metrica.md

@@ -1,5 +1,5 @@
 ---
-toc_priority: 14
+toc_priority: 15
 toc_title: Yandex.Metrica Data
 ---
 

docs/en/getting-started/example-datasets/nyc-taxi.md

@@ -1,5 +1,5 @@
 ---
-toc_priority: 16
+toc_priority: 20
 toc_title: New York Taxi Data
 ---
 

docs/en/getting-started/example-datasets/ontime.md

@@ -1,5 +1,5 @@
 ---
-toc_priority: 15
+toc_priority: 21
 toc_title: OnTime
 ---
 

docs/en/getting-started/example-datasets/star-schema.md

@@ -1,5 +1,5 @@
 ---
-toc_priority: 20
+toc_priority: 16
 toc_title: Star Schema Benchmark
 ---
 

docs/en/getting-started/example-datasets/wikistat.md

@@ -1,5 +1,5 @@
 ---
-toc_priority: 18
+toc_priority: 17
 toc_title: WikiStat
 ---
 

docs/en/interfaces/formats.md

@@ -460,7 +460,7 @@ See also the [JSONEachRow](#jsoneachrow) format.
 
 ## JSONString {#jsonstring}
 
-Differs from JSON only in that data fields are output in strings, not in typed json values.
+Differs from JSON only in that data fields are output in strings, not in typed JSON values.
 
 Example:
 
@@ -596,7 +596,7 @@ When inserting the data, you should provide a separate JSON value for each row.
 ## JSONEachRowWithProgress {#jsoneachrowwithprogress}
 ## JSONStringEachRowWithProgress {#jsonstringeachrowwithprogress}
 
-Differs from JSONEachRow/JSONStringEachRow in that ClickHouse will also yield progress information as JSON objects.
+Differs from `JSONEachRow`/`JSONStringEachRow` in that ClickHouse will also yield progress information as JSON values.
 
 ```json
 {"row":{"'hello'":"hello","multiply(42, number)":"0","range(5)":[0,1,2,3,4]}}
@@ -608,7 +608,7 @@ Differs from JSONEachRow/JSONStringEachRow in that ClickHouse will also yield pr
 ## JSONCompactEachRowWithNamesAndTypes {#jsoncompacteachrowwithnamesandtypes}
 ## JSONCompactStringEachRowWithNamesAndTypes {#jsoncompactstringeachrowwithnamesandtypes}
 
-Differs from JSONCompactEachRow/JSONCompactStringEachRow in that the column names and types are written as the first two rows.
+Differs from `JSONCompactEachRow`/`JSONCompactStringEachRow` in that the column names and types are written as the first two rows.
 
 ```json
 ["'hello'", "multiply(42, number)", "range(5)"]

docs/en/interfaces/third-party/client-libraries.md

@@ -6,7 +6,7 @@ toc_title: Client Libraries
 # Client Libraries from Third-party Developers {#client-libraries-from-third-party-developers}
 
 !!! warning "Disclaimer"
-    Yandex does **not** maintain the libraries listed below and haven’t done any extensive testing to ensure their quality.
+    Yandex does **not** maintain the libraries listed below and hasn’t done any extensive testing to ensure their quality.
 
 -   Python
     -   [infi.clickhouse_orm](https://github.com/Infinidat/infi.clickhouse_orm)

docs/en/operations/system-tables/crash-log.md

@@ -0,0 +1,48 @@
+# system.crash_log {#system-tables_crash_log}
+
+Contains information about stack traces for fatal errors. The table does not exist in the database by default, it is created only when fatal errors occur.
+
+Columns:
+
+-   `event_date` ([Datetime](../../sql-reference/data-types/datetime.md)) — Date of the event.
+-   `event_time` ([Datetime](../../sql-reference/data-types/datetime.md)) — Time of the event.
+-   `timestamp_ns` ([UInt64](../../sql-reference/data-types/int-uint.md)) — Timestamp of the event with nanoseconds.
+-   `signal` ([Int32](../../sql-reference/data-types/int-uint.md)) — Signal number.
+-   `thread_id` ([UInt64](../../sql-reference/data-types/int-uint.md)) — Thread ID.
+-   `query_id` ([String](../../sql-reference/data-types/string.md)) — Query ID.
+-   `trace` ([Array](../../sql-reference/data-types/array.md)([UInt64](../../sql-reference/data-types/int-uint.md))) — Stack trace at the moment of crash. Each element is a virtual memory address inside ClickHouse server process.
+-   `trace_full` ([Array](../../sql-reference/data-types/array.md)([String](../../sql-reference/data-types/string.md))) — Stack trace at the moment of crash. Each element contains a called method inside ClickHouse server process.
+-   `version` ([String](../../sql-reference/data-types/string.md)) — ClickHouse server version.
+-   `revision` ([UInt32](../../sql-reference/data-types/int-uint.md)) — ClickHouse server revision.
+-   `build_id` ([String](../../sql-reference/data-types/string.md)) — BuildID that is generated by compiler.
+
+**Example**
+
+Query:
+
+``` sql
+SELECT * FROM system.crash_log ORDER BY event_time DESC LIMIT 1;
+```
+
+Result (not full):
+
+``` text
+Row 1:
+──────
+event_date:   2020-10-14
+event_time:   2020-10-14 15:47:40
+timestamp_ns: 1602679660271312710
+signal:       11
+thread_id:    23624
+query_id:     428aab7c-8f5c-44e9-9607-d16b44467e69
+trace:        [188531193,...]
+trace_full:   ['3. DB::(anonymous namespace)::FunctionFormatReadableTimeDelta::executeImpl(std::__1::vector<DB::ColumnWithTypeAndName, std::__1::allocator<DB::ColumnWithTypeAndName> >&, std::__1::vector<unsigned long, std::__1::allocator<unsigned long> > const&, unsigned long, unsigned long) const @ 0xb3cc1f9 in /home/username/work/ClickHouse/build/programs/clickhouse',...]
+version:      ClickHouse 20.11.1.1
+revision:     54442
+build_id:
+```
+
+**See also**
+-   [trace_log](../../operations/system-tables/trace_log.md) system table
+
+[Original article](https://clickhouse.tech/docs/en/operations/system-tables/crash-log)

docs/en/operations/system-tables/query_log.md

@@ -20,8 +20,8 @@ The `system.query_log` table registers two kinds of queries:
 
 Each query creates one or two rows in the `query_log` table, depending on the status (see the `type` column) of the query:
 
-1.  If the query execution was successful, two rows with the `QueryStart` and `QueryFinish` types are created .
+1.  If the query execution was successful, two rows with the `QueryStart` and `QueryFinish` types are created.
-2.  If an error occurred during query processing, two events with the `QueryStart` and `ExceptionWhileProcessing` types are created .
+2.  If an error occurred during query processing, two events with the `QueryStart` and `ExceptionWhileProcessing` types are created.
 3.  If an error occurred before launching the query, a single event with the `ExceptionBeforeStart` type is created.
 
 Columns:
@@ -37,8 +37,8 @@ Columns:
 -   `query_start_time` ([DateTime](../../sql-reference/data-types/datetime.md)) — Start time of query execution.
 -   `query_start_time_microseconds` ([DateTime64](../../sql-reference/data-types/datetime64.md)) — Start time of query execution with microsecond precision.
 -   `query_duration_ms` ([UInt64](../../sql-reference/data-types/int-uint.md#uint-ranges)) — Duration of query execution in milliseconds.
--   `read_rows` ([UInt64](../../sql-reference/data-types/int-uint.md#uint-ranges)) — Total number or rows read from all tables and table functions participated in query. It includes usual subqueries, subqueries for `IN` and `JOIN`. For distributed queries `read_rows` includes the total number of rows read at all replicas. Each replica sends it’s `read_rows` value, and the server-initiator of the query summarize all received and local values. The cache volumes doesn’t affect this value.
+-   `read_rows` ([UInt64](../../sql-reference/data-types/int-uint.md#uint-ranges)) — Total number of rows read from all tables and table functions participated in query. It includes usual subqueries, subqueries for `IN` and `JOIN`. For distributed queries `read_rows` includes the total number of rows read at all replicas. Each replica sends it’s `read_rows` value, and the server-initiator of the query summarizes all received and local values. The cache volumes don’t affect this value.
--   `read_bytes` ([UInt64](../../sql-reference/data-types/int-uint.md#uint-ranges)) — Total number or bytes read from all tables and table functions participated in query. It includes usual subqueries, subqueries for `IN` and `JOIN`. For distributed queries `read_bytes` includes the total number of rows read at all replicas. Each replica sends it’s `read_bytes` value, and the server-initiator of the query summarize all received and local values. The cache volumes doesn’t affect this value.
+-   `read_bytes` ([UInt64](../../sql-reference/data-types/int-uint.md#uint-ranges)) — Total number of bytes read from all tables and table functions participated in query. It includes usual subqueries, subqueries for `IN` and `JOIN`. For distributed queries `read_bytes` includes the total number of rows read at all replicas. Each replica sends it’s `read_bytes` value, and the server-initiator of the query summarizes all received and local values. The cache volumes don’t affect this value.
 -   `written_rows` ([UInt64](../../sql-reference/data-types/int-uint.md#uint-ranges)) — For `INSERT` queries, the number of written rows. For other queries, the column value is 0.
 -   `written_bytes` ([UInt64](../../sql-reference/data-types/int-uint.md#uint-ranges)) — For `INSERT` queries, the number of written bytes. For other queries, the column value is 0.
 -   `result_rows` ([UInt64](../../sql-reference/data-types/int-uint.md#uint-ranges)) — Number of rows in a result of the `SELECT` query, or a number of rows in the `INSERT` query.

docs/en/operations/system-tables/query_thread_log.md

@@ -1,6 +1,6 @@
 # system.query_thread_log {#system_tables-query_thread_log}
 
-Contains information about threads which execute queries, for example, thread name, thread start time, duration of query processing.
+Contains information about threads that execute queries, for example, thread name, thread start time, duration of query processing.
 
 To start logging:
 

docs/en/operations/system-tables/text_log.md

@@ -1,6 +1,6 @@
 # system.text_log {#system_tables-text_log}
 
-Contains logging entries. Logging level which goes to this table can be limited with `text_log.level` server setting.
+Contains logging entries. The logging level which goes to this table can be limited to the `text_log.level` server setting.
 
 Columns:
 

docs/en/operations/system-tables/trace_log.md

@@ -18,7 +18,7 @@ Columns:
 
 -   `revision` ([UInt32](../../sql-reference/data-types/int-uint.md)) — ClickHouse server build revision.
 
-    When connecting to server by `clickhouse-client`, you see the string similar to `Connected to ClickHouse server version 19.18.1 revision 54429.`. This field contains the `revision`, but not the `version` of a server.
+    When connecting to the server by `clickhouse-client`, you see the string similar to `Connected to ClickHouse server version 19.18.1 revision 54429.`. This field contains the `revision`, but not the `version` of a server.
 
 -   `timer_type` ([Enum8](../../sql-reference/data-types/enum.md)) — Timer type:
 

docs/en/sql-reference/functions/uuid-functions.md

@@ -61,6 +61,54 @@ SELECT toUUID('61f0c404-5cb3-11e7-907b-a6006ad3dba0') AS uuid
 └──────────────────────────────────────┘
 ```
 
+## toUUIDOrNull (x) {#touuidornull-x}
+
+It takes an argument of type String and tries to parse it into UUID. If failed, returns NULL.
+
+``` sql
+toUUIDOrNull(String)
+```
+
+**Returned value**
+
+The Nullable(UUID) type value.
+
+**Usage example**
+
+``` sql
+SELECT toUUIDOrNull('61f0c404-5cb3-11e7-907b-a6006ad3dba0T') AS uuid
+```
+
+``` text
+┌─uuid─┐
+│ ᴺᵁᴸᴸ │
+└──────┘
+```
+
+## toUUIDOrZero (x) {#touuidorzero-x}
+
+It takes an argument of type String and tries to parse it into UUID. If failed, returns zero UUID.
+
+``` sql
+toUUIDOrZero(String)
+```
+
+**Returned value**
+
+The UUID type value.
+
+**Usage example**
+
+``` sql
+SELECT toUUIDOrZero('61f0c404-5cb3-11e7-907b-a6006ad3dba0T') AS uuid
+```
+
+``` text
+┌─────────────────────────────────uuid─┐
+│ 00000000-0000-0000-0000-000000000000 │
+└──────────────────────────────────────┘
+```
+
 ## UUIDStringToNum {#uuidstringtonum}
 
 Accepts a string containing 36 characters in the format `xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx`, and returns it as a set of bytes in a [FixedString(16)](../../sql-reference/data-types/fixedstring.md).

docs/en/sql-reference/operators/index.md

@@ -1,5 +1,5 @@
 ---
-toc_priority: 37
+toc_priority: 38
 toc_title: Operators
 ---
 

docs/en/sql-reference/statements/alter/index.md

@@ -1,5 +1,5 @@
 ---
-toc_priority: 36
+toc_priority: 35
 toc_title: ALTER
 ---
 

docs/en/sql-reference/statements/alter/sample-by.md

@@ -5,16 +5,16 @@ toc_title: SAMPLE BY
 
 # Manipulating Sampling-Key Expressions {#manipulations-with-sampling-key-expressions}
 
+Syntax:
+
 ``` sql
 ALTER TABLE [db].name [ON CLUSTER cluster] MODIFY SAMPLE BY new_expression
 ```
 
 The command changes the [sampling key](../../../engines/table-engines/mergetree-family/mergetree.md) of the table to `new_expression` (an expression or a tuple of expressions).
 
-The command is lightweight in a sense that it only changes metadata. The primary key must contain the new sample key.
+The command is lightweight in the sense that it only changes metadata. The primary key must contain the new sample key.
 
 !!! note "Note"
-    It only works for tables in the [`MergeTree`](../../../engines/table-engines/mergetree-family/mergetree.md) family (including
+    It only works for tables in the [MergeTree](../../../engines/table-engines/mergetree-family/mergetree.md) family (including
 [replicated](../../../engines/table-engines/mergetree-family/replication.md) tables).
-
-

docs/en/sql-reference/statements/attach.md

@@ -1,5 +1,5 @@
 ---
-toc_priority: 42
+toc_priority: 40
 toc_title: ATTACH
 ---
 

docs/en/sql-reference/statements/check-table.md

@@ -1,5 +1,5 @@
 ---
-toc_priority: 43
+toc_priority: 41
 toc_title: CHECK
 ---
 

docs/en/sql-reference/statements/create/database.md

@@ -1,5 +1,5 @@
 ---
-toc_priority: 1
+toc_priority: 35
 toc_title: DATABASE
 ---
 

docs/en/sql-reference/statements/create/dictionary.md

@@ -1,5 +1,5 @@
 ---
-toc_priority: 4
+toc_priority: 38
 toc_title: DICTIONARY
 ---
 

docs/en/sql-reference/statements/create/index.md

@@ -1,6 +1,6 @@
 ---
 toc_folder_title: CREATE
-toc_priority: 35
+toc_priority: 34
 toc_title: Overview
 ---
 

docs/en/sql-reference/statements/create/quota.md

@@ -1,5 +1,5 @@
 ---
-toc_priority: 8
+toc_priority: 42
 toc_title: QUOTA
 ---
 

docs/en/sql-reference/statements/create/role.md

@@ -1,5 +1,5 @@
 ---
-toc_priority: 6
+toc_priority: 40
 toc_title: ROLE
 ---
 

docs/en/sql-reference/statements/create/row-policy.md

@@ -1,5 +1,5 @@
 ---
-toc_priority: 7
+toc_priority: 41
 toc_title: ROW POLICY
 ---
 

docs/en/sql-reference/statements/create/settings-profile.md

@@ -1,5 +1,5 @@
 ---
-toc_priority: 9
+toc_priority: 43
 toc_title: SETTINGS PROFILE
 ---
 

docs/en/sql-reference/statements/create/table.md

@@ -1,5 +1,5 @@
 ---
-toc_priority: 2
+toc_priority: 36
 toc_title: TABLE
 ---
 

docs/en/sql-reference/statements/create/user.md

@@ -1,5 +1,5 @@
 ---
-toc_priority: 5
+toc_priority: 39
 toc_title: USER
 ---
 

docs/en/sql-reference/statements/create/view.md

@@ -1,5 +1,5 @@
 ---
-toc_priority: 3
+toc_priority: 37
 toc_title: VIEW
 ---
 

docs/en/sql-reference/statements/describe-table.md

@@ -1,5 +1,5 @@
 ---
-toc_priority: 44
+toc_priority: 42
 toc_title: DESCRIBE
 ---
 

docs/en/sql-reference/statements/detach.md

@@ -1,5 +1,5 @@
 ---
-toc_priority: 45
+toc_priority: 43
 toc_title: DETACH
 ---
 

docs/en/sql-reference/statements/drop.md

@@ -1,88 +1,100 @@
 ---
-toc_priority: 46
+toc_priority: 44
 toc_title: DROP
 ---
 
 # DROP Statements {#drop}
 
-Deletes existing entity. If `IF EXISTS` clause is specified, these queries doesn’t return an error if the entity doesn’t exist.
+Deletes existing entity. If the `IF EXISTS` clause is specified, these queries don’t return an error if the entity doesn’t exist.
 
 ## DROP DATABASE {#drop-database}
 
+Deletes all tables inside the `db` database, then deletes the `db` database itself.
+
+Syntax:
+
 ``` sql
 DROP DATABASE [IF EXISTS] db [ON CLUSTER cluster]
 ```
 
-Deletes all tables inside the `db` database, then deletes the ‘db’ database itself.
-
 ## DROP TABLE {#drop-table}
 
+Deletes the table.
+
+Syntax:
+
 ``` sql
 DROP [TEMPORARY] TABLE [IF EXISTS] [db.]name [ON CLUSTER cluster]
 ```
 
-Deletes the table.
-
 ## DROP DICTIONARY {#drop-dictionary}
 
+Deletes the dictionary.
+
+Syntax:
+
 ``` sql
 DROP DICTIONARY [IF EXISTS] [db.]name
 ```
 
-Deletes the dictionary.
-
 ## DROP USER {#drop-user-statement}
 
+Deletes a user.
+
+Syntax:
+
 ``` sql
 DROP USER [IF EXISTS] name [,...] [ON CLUSTER cluster_name]
 ```
 
-Deletes a user.
-
 ## DROP ROLE {#drop-role-statement}
 
+Deletes a role. The deleted role is revoked from all the entities where it was assigned.
+
+Syntax:
+
 ``` sql
 DROP ROLE [IF EXISTS] name [,...] [ON CLUSTER cluster_name]
 ```
 
-Deletes a role.
-
-Deleted role is revoked from all the entities where it was assigned.
-
 ## DROP ROW POLICY {#drop-row-policy-statement}
 
+Deletes a row policy. Deleted row policy is revoked from all the entities where it was assigned.
+
+Syntax:
+
 ``` sql
 DROP [ROW] POLICY [IF EXISTS] name [,...] ON [database.]table [,...] [ON CLUSTER cluster_name]
 ```
 
-Deletes a row policy.
-
-Deleted row policy is revoked from all the entities where it was assigned.
-
 ## DROP QUOTA {#drop-quota-statement}
 
+Deletes a quota. The deleted quota is revoked from all the entities where it was assigned.
+
+Syntax:
+
 ``` sql
 DROP QUOTA [IF EXISTS] name [,...] [ON CLUSTER cluster_name]
 ```
 
-Deletes a quota.
-
-Deleted quota is revoked from all the entities where it was assigned.
-
 ## DROP SETTINGS PROFILE {#drop-settings-profile-statement}
 
+Deletes a settings profile. The deleted settings profile is revoked from all the entities where it was assigned.
+
+Syntax:
+
 ``` sql
 DROP [SETTINGS] PROFILE [IF EXISTS] name [,...] [ON CLUSTER cluster_name]
 ```
 
-Deletes a settings profile.
-
-Deleted settings profile is revoked from all the entities where it was assigned.
-
 ## DROP VIEW {#drop-view}
 
+Deletes a view. Views can be deleted by a `DROP TABLE` command as well but `DROP VIEW` checks that `[db.]name` is a view.
+
+Syntax:
+
 ``` sql
 DROP VIEW [IF EXISTS] [db.]name [ON CLUSTER cluster]
 ```
 
-Deletes a view. Views can be deleted by a `DROP TABLE` command as well but `DROP VIEW` checks that `[db.]name` is a view.
+[Оriginal article](https://clickhouse.tech/docs/en/sql-reference/statements/drop/) <!--hide-->

docs/en/sql-reference/statements/exists.md

@@ -1,5 +1,5 @@
 ---
-toc_priority: 47
+toc_priority: 45
 toc_title: EXISTS
 ---
 

docs/en/sql-reference/statements/grant.md

@@ -1,5 +1,5 @@
 ---
-toc_priority: 39
+toc_priority: 38
 toc_title: GRANT
 ---
 

docs/en/sql-reference/statements/insert-into.md

@@ -1,5 +1,5 @@
 ---
-toc_priority: 34
+toc_priority: 33
 toc_title: INSERT INTO
 ---
 

docs/en/sql-reference/statements/kill.md

@@ -1,5 +1,5 @@
 ---
-toc_priority: 48
+toc_priority: 46
 toc_title: KILL
 ---
 

docs/en/sql-reference/statements/optimize.md

@@ -1,5 +1,5 @@
 ---
-toc_priority: 49
+toc_priority: 47
 toc_title: OPTIMIZE
 ---
 

docs/en/sql-reference/statements/rename.md

@@ -1,5 +1,5 @@
 ---
-toc_priority: 50
+toc_priority: 48
 toc_title: RENAME
 ---
 

docs/en/sql-reference/statements/revoke.md

@@ -1,5 +1,5 @@
 ---
-toc_priority: 40
+toc_priority: 39
 toc_title: REVOKE
 ---
 

docs/en/sql-reference/statements/select/index.md

@@ -1,7 +1,7 @@
 ---
 title: SELECT Query
 toc_folder_title: SELECT
-toc_priority: 33
+toc_priority: 32
 toc_title: Overview
 ---
 

docs/en/sql-reference/statements/set-role.md

@@ -1,5 +1,5 @@
 ---
-toc_priority: 52
+toc_priority: 51
 toc_title: SET ROLE
 ---
 

docs/en/sql-reference/statements/set.md

@@ -1,5 +1,5 @@
 ---
-toc_priority: 51
+toc_priority: 49
 toc_title: SET
 ---
 

docs/en/sql-reference/statements/show.md

@@ -1,5 +1,5 @@
 ---
-toc_priority: 38
+toc_priority: 37
 toc_title: SHOW
 ---
 

docs/en/sql-reference/statements/system.md

@@ -1,5 +1,5 @@
 ---
-toc_priority: 37
+toc_priority: 36
 toc_title: SYSTEM
 ---
 

docs/en/sql-reference/statements/truncate.md

@@ -1,5 +1,5 @@
 ---
-toc_priority: 53
+toc_priority: 52
 toc_title: TRUNCATE
 ---
 

docs/en/sql-reference/statements/use.md

@@ -1,5 +1,5 @@
 ---
-toc_priority: 54
+toc_priority: 53
 toc_title: USE
 ---
 

docs/ru/commercial/cloud.md

@@ -1,3 +1,8 @@
+---
+toc_priority: 1
+toc_title: "\u041f\u043e\u0441\u0442\u0430\u0432\u0449\u0438\u043a\u0438\u0020\u043e\u0431\u043b\u0430\u0447\u043d\u044b\u0445\u0020\u0443\u0441\u043b\u0443\u0433\u0020\u0043\u006c\u0069\u0063\u006b\u0048\u006f\u0075\u0073\u0065"
+---
+
 # Поставщики облачных услуг ClickHouse {#clickhouse-cloud-service-providers}
 
 !!! info "Инфо"

docs/ru/development/architecture.md

@@ -1,3 +1,8 @@
+---
+toc_priority: 62
+toc_title: "\u041e\u0431\u0437\u043e\u0440\u0020\u0430\u0440\u0445\u0438\u0442\u0435\u043a\u0442\u0443\u0440\u044b\u0020\u0043\u006c\u0069\u0063\u006b\u0048\u006f\u0075\u0073\u0065"
+---
+
 # Обзор архитектуры ClickHouse {#overview-of-clickhouse-architecture}
 
 ClickHouse - полноценная колоночная СУБД. Данные хранятся в колонках, а в процессе обработки - в массивах (векторах или фрагментах (chunk’ах) колонок). По возможности операции выполняются на массивах, а не на индивидуальных значениях. Это называется “векторизованное выполнения запросов” (vectorized query execution), и помогает снизить стоимость фактической обработки данных.

docs/ru/development/browse-code.md

@@ -1,3 +1,9 @@
+---
+toc_priority: 71
+toc_title: "\u041d\u0430\u0432\u0438\u0433\u0430\u0446\u0438\u044f\u0020\u043f\u043e\u0020\u043a\u043e\u0434\u0443\u0020\u0043\u006c\u0069\u0063\u006b\u0048\u006f\u0075\u0073\u0065"
+---
+
+
 # Навигация по коду ClickHouse {#navigatsiia-po-kodu-clickhouse}
 
 Для навигации по коду онлайн доступен **Woboq**, он расположен [здесь](https://clickhouse.tech/codebrowser/html_report///ClickHouse/src/index.html). В нём реализовано удобное перемещение между исходными файлами, семантическая подсветка, подсказки, индексация и поиск. Слепок кода обновляется ежедневно.

docs/ru/development/contrib.md

@@ -1,3 +1,9 @@
+---
+toc_priority: 70
+toc_title: "\u0418\u0441\u043f\u043e\u043b\u044c\u0437\u0443\u0435\u043c\u044b\u0435\u0020\u0441\u0442\u043e\u0440\u043e\u043d\u043d\u0438\u0435\u0020\u0431\u0438\u0431\u043b\u0438\u043e\u0442\u0435\u043a\u0438"
+---
+
+
 # Используемые сторонние библиотеки {#ispolzuemye-storonnie-biblioteki}
 
 | Библиотека          | Лицензия                                                                                                                                     |

docs/ru/development/developer-instruction.md

@@ -1,3 +1,8 @@
+---
+toc_priority: 61
+toc_title: "\u0418\u043d\u0441\u0442\u0440\u0443\u043a\u0446\u0438\u044f\u0020\u0434\u043b\u044f\u0020\u0440\u0430\u0437\u0440\u0430\u0431\u043e\u0442\u0447\u0438\u043a\u043e\u0432"
+---
+
 # Инструкция для разработчиков
 
 Сборка ClickHouse поддерживается на Linux, FreeBSD, Mac OS X.

docs/ru/development/style.md

@@ -1,3 +1,9 @@
+---
+toc_priority: 68
+toc_title: "\u041a\u0430\u043a\u0020\u043f\u0438\u0441\u0430\u0442\u044c\u0020\u043a\u043e\u0434\u0020\u043d\u0430\u0020\u0043\u002b\u002b"
+---
+
+
 # Как писать код на C++ {#kak-pisat-kod-na-c}
 
 ## Общее {#obshchee}

docs/ru/engines/database-engines/index.md

@@ -1,3 +1,10 @@
+---
+toc_folder_title: "\u0414\u0432\u0438\u0436\u043a\u0438\u0020\u0431\u0430\u0437\u0020\u0434\u0430\u043d\u043d\u044b\u0445"
+toc_priority: 27
+toc_title: "\u0412\u0432\u0435\u0434\u0435\u043d\u0438\u0435"
+---
+
+
 # Движки баз данных {#dvizhki-baz-dannykh}
 
 Движки баз данных обеспечивают работу с таблицами.

docs/ru/engines/database-engines/lazy.md

@@ -1,3 +1,8 @@
+---
+toc_priority: 31
+toc_title: Lazy
+---
+
 # Lazy {#lazy}
 
 Сохраняет таблицы только в оперативной памяти `expiration_time_in_seconds` через несколько секунд после последнего доступа. Может использоваться только с таблицами \*Log.

docs/ru/engines/database-engines/mysql.md

@@ -1,3 +1,8 @@
+---
+toc_priority: 30
+toc_title: MySQL
+---
+
 # MySQL {#mysql}
 
 Позволяет подключаться к базам данных на удалённом MySQL сервере и выполнять запросы `INSERT` и `SELECT` для обмена данными между ClickHouse и MySQL.

docs/ru/engines/index.md

@@ -1,6 +1,6 @@
 ---
-toc_folder_title: "\u0414\u0432\u0438\u0436\u043A\u0438"
+toc_folder_title: "\u0045\u006e\u0067\u0069\u006e\u0065\u0073"
+toc_hidden: true
 toc_priority: 25
+toc_title: hidden
 ---
-
-

docs/ru/engines/table-engines/index.md

@@ -1,3 +1,10 @@
+---
+toc_folder_title: "\u0414\u0432\u0438\u0436\u043a\u0438\u0020\u0442\u0430\u0431\u043b\u0438\u0446"
+toc_priority: 26
+toc_title: "\u0412\u0432\u0435\u0434\u0435\u043d\u0438\u0435"
+---
+
+
 # Движки таблиц {#table_engines}
 
 Движок таблицы (тип таблицы) определяет:

docs/ru/engines/table-engines/integrations/hdfs.md

@@ -1,3 +1,8 @@
+---
+toc_priority: 4
+toc_title: HDFS
+---
+
 # HDFS {#table_engines-hdfs}
 
 Управляет данными в HDFS. Данный движок похож на движки [File](../special/file.md#table_engines-file) и [URL](../special/url.md#table_engines-url).

docs/ru/engines/table-engines/integrations/index.md

@@ -1,5 +1,5 @@
 ---
-toc_folder_title: Integrations
+toc_folder_title: "\u0414\u0432\u0438\u0436\u043a\u0438\u0020\u0442\u0430\u0431\u043b\u0438\u0446\u0020\u0434\u043b\u044f\u0020\u0438\u043d\u0442\u0435\u0433\u0440\u0430\u0446\u0438\u0438"
 toc_priority: 30
 ---
 

docs/ru/engines/table-engines/integrations/jdbc.md

@@ -1,3 +1,8 @@
+---
+toc_priority: 2
+toc_title: JDBC
+---
+
 # JDBC {#table-engine-jdbc}
 
 Позволяет ClickHouse подключаться к внешним базам данных с помощью [JDBC](https://en.wikipedia.org/wiki/Java_Database_Connectivity).

docs/ru/engines/table-engines/integrations/kafka.md

@@ -1,3 +1,8 @@
+---
+toc_priority: 5
+toc_title: Kafka
+---
+
 # Kafka {#kafka}
 
 Движок работает с [Apache Kafka](http://kafka.apache.org/).

docs/ru/engines/table-engines/integrations/mysql.md

@@ -1,3 +1,8 @@
+---
+toc_priority: 3
+toc_title: MySQL
+---
+
 # MySQL {#mysql}
 
 Движок MySQL позволяет выполнять запросы `SELECT` над данными, хранящимися на удалённом MySQL сервере.

docs/ru/engines/table-engines/integrations/odbc.md

@@ -1,3 +1,8 @@
+---
+toc_priority: 1
+toc_title: ODBC
+---
+
 # ODBC {#table-engine-odbc}
 
 Позволяет ClickHouse подключаться к внешним базам данных с помощью [ODBC](https://en.wikipedia.org/wiki/Open_Database_Connectivity).

docs/ru/engines/table-engines/log-family/index.md

@@ -1,6 +1,6 @@
 ---
-toc_folder_title: Семейство Log
+toc_folder_title: "\u0421\u0435\u043c\u0435\u0439\u0441\u0442\u0432\u043e\u0020\u004c\u006f\u0067"
-toc_title: Введение
+toc_title: "\u0412\u0432\u0435\u0434\u0435\u043d\u0438\u0435"
 toc_priority: 29
 ---
 

docs/ru/engines/table-engines/log-family/log.md

@@ -1,3 +1,8 @@
+---
+toc_priority: 33
+toc_title: Log
+---
+
 # Log {#log}
 
 Движок относится к семейству движков Log. Смотрите общие свойства и различия движков в статье [Семейство Log](index.md).

docs/ru/engines/table-engines/log-family/stripelog.md

@@ -1,3 +1,8 @@
+---
+toc_priority: 32
+toc_title: StripeLog
+---
+
 # StripeLog {#stripelog}
 
 Движок относится к семейству движков Log. Смотрите общие свойства и различия движков в статье [Семейство Log](index.md).

docs/ru/engines/table-engines/log-family/tinylog.md

@@ -1,3 +1,8 @@
+---
+toc_priority: 34
+toc_title: TinyLog
+---
+
 # TinyLog {#tinylog}
 
 Движок относится к семейству движков Log. Смотрите общие свойства и различия движков в статье [Семейство Log](index.md).

docs/ru/engines/table-engines/mergetree-family/aggregatingmergetree.md

@@ -1,3 +1,8 @@
+---
+toc_priority: 35
+toc_title: AggregatingMergeTree
+---
+
 # AggregatingMergeTree {#aggregatingmergetree}
 
 Движок наследует функциональность [MergeTree](mergetree.md#table_engines-mergetree), изменяя логику слияния кусков данных. Все строки с одинаковым первичным ключом (точнее, с одинаковым [ключом сортировки](mergetree.md)) ClickHouse заменяет на одну (в пределах одного куска данных), которая хранит объединение состояний агрегатных функций.

docs/ru/engines/table-engines/mergetree-family/collapsingmergetree.md

@@ -1,3 +1,8 @@
+---
+toc_priority: 36
+toc_title: CollapsingMergeTree
+---
+
 # CollapsingMergeTree {#table_engine-collapsingmergetree}
 
 Движок наследует функциональность от [MergeTree](mergetree.md) и добавляет в алгоритм слияния кусков данных логику сворачивания (удаления) строк.

docs/ru/engines/table-engines/mergetree-family/custom-partitioning-key.md

@@ -1,3 +1,9 @@
+---
+toc_priority: 32
+toc_title: "\u041f\u0440\u043e\u0438\u0437\u0432\u043e\u043b\u044c\u043d\u044b\u0439\u0020\u043a\u043b\u044e\u0447\u0020\u043f\u0430\u0440\u0442\u0438\u0446\u0438\u043e\u043d\u0438\u0440\u043e\u0432\u0430\u043d\u0438\u044f"
+---
+
+
 # Произвольный ключ партиционирования {#proizvolnyi-kliuch-partitsionirovaniia}
 
 Партиционирование данных доступно для таблиц семейства [MergeTree](mergetree.md) (включая [реплицированные таблицы](replication.md)). Таблицы [MaterializedView](../special/materializedview.md#materializedview), созданные на основе таблиц MergeTree, также поддерживают партиционирование.

docs/ru/engines/table-engines/mergetree-family/graphitemergetree.md

@@ -1,3 +1,8 @@
+---
+toc_priority: 38
+toc_title: GraphiteMergeTree
+---
+
 # GraphiteMergeTree {#graphitemergetree}
 
 Движок предназначен для прореживания и агрегирования/усреднения (rollup) данных [Graphite](http://graphite.readthedocs.io/en/latest/index.html). Он может быть интересен разработчикам, которые хотят использовать ClickHouse как хранилище данных для Graphite.

docs/ru/engines/table-engines/mergetree-family/index.md

@@ -1,6 +1,5 @@
 ---
 toc_folder_title: MergeTree Family
 toc_priority: 28
+toc_title: "\u0412\u0432\u0435\u0434\u0435\u043d\u0438\u0435"
 ---
-
-

docs/ru/engines/table-engines/mergetree-family/replacingmergetree.md

@@ -1,3 +1,8 @@
+---
+toc_priority: 33
+toc_title: ReplacingMergeTree
+---
+
 # ReplacingMergeTree {#replacingmergetree}
 
 Движок отличается от [MergeTree](mergetree.md#table_engines-mergetree) тем, что выполняет удаление дублирующихся записей с одинаковым значением [ключа сортировки](mergetree.md)).

docs/ru/engines/table-engines/mergetree-family/replication.md

@@ -1,3 +1,8 @@
+---
+toc_priority: 31
+toc_title: "\u0420\u0435\u043f\u043b\u0438\u043a\u0430\u0446\u0438\u044f\u0020\u0434\u0430\u043d\u043d\u044b\u0445"
+---
+
 # Репликация данных {#table_engines-replication}
 
 Репликация поддерживается только для таблиц семейства MergeTree:

docs/ru/engines/table-engines/mergetree-family/summingmergetree.md

@@ -1,3 +1,8 @@
+---
+toc_priority: 34
+toc_title: SummingMergeTree
+---
+
 # SummingMergeTree {#summingmergetree}
 
 Движок наследует функциональность [MergeTree](mergetree.md#table_engines-mergetree). Отличие заключается в том, что для таблиц `SummingMergeTree` при слиянии кусков данных ClickHouse все строки с одинаковым первичным ключом (точнее, с одинаковым [ключом сортировки](mergetree.md)) заменяет на одну, которая хранит только суммы значений из столбцов с цифровым типом данных. Если ключ сортировки подобран таким образом, что одному значению ключа соответствует много строк, это значительно уменьшает объём хранения и ускоряет последующую выборку данных.

docs/ru/engines/table-engines/mergetree-family/versionedcollapsingmergetree.md

@@ -1,3 +1,8 @@
+---
+toc_priority: 37
+toc_title: VersionedCollapsingMergeTree
+---
+
 # VersionedCollapsingMergeTree {#versionedcollapsingmergetree}
 
 Движок:

docs/ru/engines/table-engines/special/buffer.md

@@ -1,3 +1,8 @@
+---
+toc_priority: 45
+toc_title: Buffer
+---
+
 # Buffer {#buffer}
 
 Буферизует записываемые данные в оперативке, периодически сбрасывая их в другую таблицу. При чтении, производится чтение данных одновременно из буфера и из другой таблицы.

docs/ru/engines/table-engines/special/dictionary.md

@@ -1,3 +1,8 @@
+---
+toc_priority: 35
+toc_title: Dictionary
+---
+
 # Dictionary {#dictionary}
 
 Движок `Dictionary` отображает данные [словаря](../../../sql-reference/dictionaries/external-dictionaries/external-dicts.md) как таблицу ClickHouse.

docs/ru/engines/table-engines/special/distributed.md

@@ -1,3 +1,8 @@
+---
+toc_priority: 33
+toc_title: Distributed
+---
+
 # Distributed {#distributed}
 
 **Движок Distributed не хранит данные самостоятельно**, а позволяет обрабатывать запросы распределённо, на нескольких серверах. Чтение автоматически распараллеливается. При чтении будут использованы индексы таблиц на удалённых серверах, если есть.

docs/ru/engines/table-engines/special/external-data.md

@@ -1,3 +1,8 @@
+---
+toc_priority: 45
+toc_title: "\u0412\u043d\u0435\u0448\u043d\u0438\u0435\u0020\u0434\u0430\u043d\u043d\u044b\u0435\u0020\u0434\u043b\u044f\u0020\u043e\u0431\u0440\u0430\u0431\u043e\u0442\u043a\u0438\u0020\u0437\u0430\u043f\u0440\u043e\u0441\u0430"
+---
+
 # Внешние данные для обработки запроса {#vneshnie-dannye-dlia-obrabotki-zaprosa}
 
 ClickHouse позволяет отправить на сервер данные, необходимые для обработки одного запроса, вместе с запросом SELECT. Такие данные будут положены во временную таблицу (см. раздел «Временные таблицы») и смогут использоваться в запросе (например, в операторах IN).

docs/ru/engines/table-engines/special/file.md

@@ -1,3 +1,8 @@
+---
+toc_priority: 37
+toc_title: File
+---
+
 # File(Format) {#table_engines-file}
 
 Управляет данными в одном файле на диске в указанном формате.

docs/ru/engines/table-engines/special/index.md

@@ -1,5 +1,5 @@
 ---
-toc_folder_title: Special
+toc_folder_title: "\u0421\u043f\u0435\u0446\u0438\u0430\u043b\u044c\u043d\u044b\u0435\u0020\u0434\u0432\u0438\u0436\u043a\u0438\u0020\u0442\u0430\u0431\u043b\u0438\u0446"
 toc_priority: 31
 ---
 

docs/ru/engines/table-engines/special/join.md

@@ -1,3 +1,8 @@
+---
+toc_priority: 40
+toc_title: Join
+---
+
 # Join {#join}
 
 Подготовленная структура данных для использования в операциях [JOIN](../../../engines/table-engines/special/join.md#select-join).

docs/ru/engines/table-engines/special/materializedview.md

@@ -1,3 +1,8 @@
+---
+toc_priority: 43
+toc_title: MaterializedView
+---
+
 # MaterializedView {#materializedview}
 
 Используется для реализации материализованных представлений (подробнее см. запрос [CREATE TABLE](../../../sql-reference/statements/create/table.md#create-table-query)). Для хранения данных, использует другой движок, который был указан при создании представления. При чтении из таблицы, просто использует этот движок.

docs/ru/engines/table-engines/special/memory.md

@@ -1,3 +1,8 @@
+---
+toc_priority: 44
+toc_title: Memory
+---
+
 # Memory {#memory}
 
 Хранит данные в оперативке, в несжатом виде. Данные хранятся именно в таком виде, в каком они получаются при чтении. То есть, само чтение из этой таблицы полностью бесплатно.

docs/ru/engines/table-engines/special/merge.md

@@ -1,3 +1,8 @@
+---
+toc_priority: 36
+toc_title: Merge
+---
+
 # Merge {#merge}
 
 Движок `Merge` (не путайте с движком `MergeTree`) не хранит данные самостоятельно, а позволяет читать одновременно из произвольного количества других таблиц.

docs/ru/engines/table-engines/special/null.md

@@ -1,4 +1,7 @@
-# Null {#null}
+---
+toc_priority: 38
+toc_title: 'Null'
+---
 
 При записи в таблицу типа Null, данные игнорируются. При чтении из таблицы типа Null, возвращается пустота.
 

docs/ru/engines/table-engines/special/set.md

@@ -1,3 +1,8 @@
+---
+toc_priority: 39
+toc_title: Set
+---
+
 # Set {#set}
 
 Представляет собой множество, постоянно находящееся в оперативке. Предназначено для использования в правой части оператора IN (смотрите раздел «Операторы IN»).

docs/ru/engines/table-engines/special/url.md

@@ -1,3 +1,8 @@
+---
+toc_priority: 41
+toc_title: URL
+---
+
 # URL(URL, Format) {#table_engines-url}
 
 Управляет данными на удаленном HTTP/HTTPS сервере. Данный движок похож

docs/ru/engines/table-engines/special/view.md

@@ -1,3 +1,8 @@
+---
+toc_priority: 42
+toc_title: View
+---
+
 # View {#table_engines-view}
 
 Используется для реализации представлений (подробнее см. запрос `CREATE VIEW`). Не хранит данные, а хранит только указанный запрос `SELECT`. При чтении из таблицы, выполняет его (с удалением из запроса всех ненужных столбцов).

docs/ru/faq/index.md

@@ -1,6 +1,6 @@
 ---
 toc_folder_title: F.A.Q.
+toc_hidden: true
 toc_priority: 76
 ---
 
-

docs/ru/getting-started/example-datasets/amplab-benchmark.md

@@ -1,3 +1,8 @@
+---
+toc_priority: 19
+toc_title: AMPLab Big Data Benchmark
+---
+
 # AMPLab Big Data Benchmark {#amplab-big-data-benchmark}
 
 См. https://amplab.cs.berkeley.edu/benchmark/

docs/ru/getting-started/example-datasets/criteo.md

@@ -1,3 +1,8 @@
+---
+toc_priority: 18
+toc_title: "\u0422\u0435\u0440\u0430\u0431\u0430\u0439\u0442\u0020\u043b\u043e\u0433\u043e\u0432\u0020\u043a\u043b\u0438\u043a\u043e\u0432\u0020\u043e\u0442\u0020\u0043\u0072\u0069\u0074\u0065\u006f"
+---
+
 # Терабайт логов кликов от Criteo {#terabait-logov-klikov-ot-criteo}
 
 Скачайте данные с http://labs.criteo.com/downloads/download-terabyte-click-logs/