Align 8 PRs

auto-increment.md

@@ -8,7 +8,11 @@ aliases: ['/docs/dev/auto-increment/']
 
 This document introduces the `AUTO_INCREMENT` column attribute, including its concept, implementation principles, auto-increment related features, and restrictions.
 
-## Concept 
+> **Note:**
+>
+> The `AUTO_INCREMENT` attribute might cause hotspot in production environments. See [Troubleshoot HotSpot Issues](/troubleshoot-hot-spot-issues.md) for details. It is recommended to use [`AUTO_RANDOM`](/auto-random.md) instead.
+
+## Concept
 
 `AUTO_INCREMENT` is a column attribute that is used to automatically fill in default column values. When the `INSERT` statement does not specify values for the `AUTO_INCREMENT` column, the system automatically assigns values to this column.
 

explain-subqueries.md

@@ -102,7 +102,7 @@ Semantically because `t3.t1_id` is guaranteed unique, it can be executed directl
 
 ## Semi join (correlated subquery)
 
-In the previous two examples, TiDB is able to perform an `INNER JOIN` operation after the data inside the subquery is made unique (via `HashAgg`) or guaranteed unique. Both joins are performed using an Index Join.
+In the previous two examples, TiDB is able to perform an `INNER JOIN` operation after the data inside the subquery is made unique (via `StreamAgg`) or guaranteed unique. Both joins are performed using an Index Join.
 
 In this example, TiDB chooses a different execution plan:
 

functions-and-operators/aggregate-group-by-functions.md

@@ -63,6 +63,8 @@ In addition, TiDB also provides the following aggregate functions:
     1 row in set (0.00 sec)
     ```
 
+Except for the `GROUP_CONCAT()` and `APPROX_PERCENTILE()` functions, all the preceding functions can serve as [Window functions](/functions-and-operators/window-functions.md).
+
 ## GROUP BY modifiers
 
 TiDB does not currently support `GROUP BY` modifiers such as `WITH ROLLUP`. We plan to add support in the future. See [TiDB #4250](https://github.com/pingcap/tidb/issues/4250).

functions-and-operators/window-functions.md

@@ -10,7 +10,7 @@ The usage of window functions in TiDB is similar to that in MySQL 8.0. For detai
 
 Because window functions reserve additional words in the parser, TiDB provides an option to disable window functions. If you receive errors parsing SQL statements after upgrading, try setting `tidb_enable_window_function=0`.
 
-TiDB supports the following window functions:
+Except for `GROUP_CONCAT()` and `APPROX_PERCENTILE()`, TiDB supports all [`GROUP BY` aggregate functions](/functions-and-operators/aggregate-group-by-functions.md). In addition, TiDB supports the following window functions:
 
 | Function name | Feature description |
 | :-------------- | :------------------------------------- |

grafana-tidb-dashboard.md

@@ -26,14 +26,14 @@ To understand the key metrics displayed on the TiDB dashboard, check the followi
     - Command Per Second: the number of commands processed by TiDB per second, which is classified according to the success or failure of command execution results
     - QPS: the number of SQL statements executed per second on all TiDB instances, which is counted according to `SELECT`, `INSERT`, `UPDATE`, and other types of statements
     - CPS By Instance: the command statistics on each TiDB instance, which is classified according to the success or failure of command execution results
-    - Failed Query OPM: the statistics of error types (such as syntax errors and primary key conflicts) according to the errors occurred when executing SQL statements per second on each TiDB instance. It contains the module in which the error occurs and the error code
+    - Failed Query OPM: the statistics of error types (such as syntax errors and primary key conflicts) according to the errors occurred when executing SQL statements per minute on each TiDB instance. It contains the module in which the error occurs and the error code
     - Slow query: the statistics of the processing time of slow queries (the time cost of the entire slow query, the time cost of Coprocessor, and the waiting time for Coprocessor scheduling). Slow queries are classified into internal and general SQL statements
     - Connection Idle Duration: the duration of idle connections
     - 999/99/95/80 Duration: the statistics of the execution time for different types of SQL statements (different percentiles)
 
 - Query Detail
     - Duration 80/95/99/999 By Instance: the statistics of the execution time for SQL statements on each TiDB instance (different percentiles)
-    - Failed Query OPM Detail: the statistics of error types (such as syntax errors and primary key conflicts) according to the errors occurred when executing SQL statements on each TiDB instance
+    - Failed Query OPM Detail: the statistics of error types (such as syntax errors and primary key conflicts) according to the errors occurred when executing SQL statements per minute on each TiDB instance
     - Internal SQL OPS: the internal SQL statements executed per second in the entire TiDB cluster. The internal SQL statements are internally executed and are generally triggered by user SQL statements or internally scheduled tasks.
 
 - Server

mysql-compatibility.md

@@ -78,6 +78,10 @@ mysql> SELECT _tidb_rowid, id FROM t;
 3 rows in set (0.01 sec)
 ```
 
+> **Note:**
+>
+> The `AUTO_INCREMENT` attribute might cause hotspot in production environments. See [Troubleshoot HotSpot Issues](/troubleshoot-hot-spot-issues.md) for details. It is recommended to use [`AUTO_RANDOM`](/auto-random.md) instead.
+
 ### Performance schema
 
 TiDB uses a combination of [Prometheus and Grafana](/tidb-monitoring-api.md) to store and query the performance monitoring metrics. Performance schema tables return empty results in TiDB.

placement-rules-in-sql.md

@@ -102,19 +102,21 @@ Rules that are attached to objects are applied *asynchronously*. To view the cur
 
 > **Note:**
 >
-> Placement options depend on labels correctly specified in the configuration of each TiKV node. For example, the `PRIMARY_REGION` option depends on the `region` label in TiKV. To see a summary of all labels available in your TiKV cluster, use the statement [`SHOW PLACEMENT LABELS`](/sql-statements/sql-statement-show-placement-labels.md):
+> - Placement options depend on labels correctly specified in the configuration of each TiKV node. For example, the `PRIMARY_REGION` option depends on the `region` label in TiKV. To see a summary of all labels available in your TiKV cluster, use the statement [`SHOW PLACEMENT LABELS`](/sql-statements/sql-statement-show-placement-labels.md):
 >
-> ```sql
-> mysql> show placement labels;
-> +--------+----------------+
-> | Key    | Values         |
-> +--------+----------------+
-> | disk   | ["ssd"]        |
-> | region | ["us-east-1"]  |
-> | zone   | ["us-east-1a"] |
-> +--------+----------------+
-> 3 rows in set (0.00 sec)
-> ```
+>    ```sql
+>    mysql> show placement labels;
+>    +--------+----------------+
+>    | Key    | Values         |
+>    +--------+----------------+
+>    | disk   | ["ssd"]        |
+>    | region | ["us-east-1"]  |
+>    | zone   | ["us-east-1a"] |
+>    +--------+----------------+
+>    3 rows in set (0.00 sec)
+>    ```
+>
+> - When you use `CREATE PLACEMENT POLICY` to create a placement policy, TiDB does not check whether the labels exist. Instead, TiDB performs the check when you attach the policy to a table.
 
 | Option Name                | Description                                                                                    |
 |----------------------------|------------------------------------------------------------------------------------------------|

schedule-replicas-by-topology-labels.md

@@ -22,7 +22,7 @@ You can use the command-line flag or set the TiKV configuration file to bind som
 
 Assume that the topology has three layers: zone > rack > host, and you can use these labels (zone, rack, host) to set the TiKV location in one of the following methods:
 
-+ Use the command-line flag:
++ Use the command-line flag to start a TiKV instance:
 
     {{< copyable "" >}}
 
@@ -49,7 +49,8 @@ You can customize the value of `location-labels`, such as `zone`, `rack`, or `ho
 
 > **Note:**
 >
-> To make configurations take effect, you must configure `location-labels` for PD and `labels` for TiKV at the same time. Otherwise, PD does not perform scheduling according to the topology.
+> - To make configurations take effect, you must configure `location-labels` for PD and `labels` for TiKV at the same time. Otherwise, PD does not perform scheduling according to the topology.
+> - If you use Placement Rules in SQL, you only need to configure `labels` for TiKV. Currently, Placement Rules in SQL is incompatible with the `location-labels` configuration of PD and ignores this configuration. It is not recommended to use `location-labels` and Placement Rules in SQL at the same time; otherwise, unexpected results might occur.
 
 To configure `location-labels`, choose one of the following methods according to your cluster situation:
 
@@ -156,6 +157,10 @@ tikv_servers:
 
 For details, see [Geo-distributed Deployment topology](/geo-distributed-deployment-topology.md).
 
+> **Note:**
+>
+> If you have not configured `replication.location-labels` in the configuration file, when you deploy a cluster using this topology file, an error might occur. It is recommended that you confirm `replication.location-labels` is configured in the configuration file before deploying a cluster.
+
 ## PD schedules based on topology label
 
 PD schedules replicas according to the label layer to make sure that different replicas of the same data are scattered as much as possible.

sql-statements/sql-statement-add-column.md

@@ -11,37 +11,37 @@ The `ALTER TABLE.. ADD COLUMN` statement adds a column to an existing table. Thi
 ## Synopsis
 
 ```ebnf+diagram
-AlterTableStmt ::=
-    'ALTER' IgnoreOptional 'TABLE' TableName ( AlterTableSpecListOpt AlterTablePartitionOpt | 'ANALYZE' 'PARTITION' PartitionNameList ( 'INDEX' IndexNameList )? AnalyzeOptionListOpt )
-
-AlterTableSpec ::=
-    TableOptionList
-|   'SET' 'TIFLASH' 'REPLICA' LengthNum LocationLabelList
-|   'CONVERT' 'TO' CharsetKw ( CharsetName | 'DEFAULT' ) OptCollate
-|   'ADD' ( ColumnKeywordOpt IfNotExists ( ColumnDef ColumnPosition | '(' TableElementList ')' ) | Constraint | 'PARTITION' IfNotExists NoWriteToBinLogAliasOpt ( PartitionDefinitionListOpt | 'PARTITIONS' NUM ) )
-|   ( ( 'CHECK' | 'TRUNCATE' ) 'PARTITION' | ( 'OPTIMIZE' | 'REPAIR' | 'REBUILD' ) 'PARTITION' NoWriteToBinLogAliasOpt ) AllOrPartitionNameList
-|   'COALESCE' 'PARTITION' NoWriteToBinLogAliasOpt NUM
-|   'DROP' ( ColumnKeywordOpt IfExists ColumnName RestrictOrCascadeOpt | 'PRIMARY' 'KEY' | 'PARTITION' IfExists PartitionNameList | ( KeyOrIndex IfExists | 'CHECK' ) Identifier | 'FOREIGN' 'KEY' IfExists Symbol )
-|   'EXCHANGE' 'PARTITION' Identifier 'WITH' 'TABLE' TableName WithValidationOpt
-|   ( 'IMPORT' | 'DISCARD' ) ( 'PARTITION' AllOrPartitionNameList )? 'TABLESPACE'
-|   'REORGANIZE' 'PARTITION' NoWriteToBinLogAliasOpt ReorganizePartitionRuleOpt
-|   'ORDER' 'BY' AlterOrderItem ( ',' AlterOrderItem )*
-|   ( 'DISABLE' | 'ENABLE' ) 'KEYS'
-|   ( 'MODIFY' ColumnKeywordOpt IfExists | 'CHANGE' ColumnKeywordOpt IfExists ColumnName ) ColumnDef ColumnPosition
-|   'ALTER' ( ColumnKeywordOpt ColumnName ( 'SET' 'DEFAULT' ( SignedLiteral | '(' Expression ')' ) | 'DROP' 'DEFAULT' ) | 'CHECK' Identifier EnforcedOrNot | 'INDEX' Identifier IndexInvisible )
-|   'RENAME' ( ( 'COLUMN' | KeyOrIndex ) Identifier 'TO' Identifier | ( 'TO' | '='? | 'AS' ) TableName )
-|   LockClause
-|   AlgorithmClause
-|   'FORCE'
-|   ( 'WITH' | 'WITHOUT' ) 'VALIDATION'
-|   'SECONDARY_LOAD'
-|   'SECONDARY_UNLOAD'
-
-ColumnDef ::=
-    ColumnName ( Type | 'SERIAL' ) ColumnOptionListOpt
-
-ColumnPosition ::=
-    ( 'FIRST' | 'AFTER' ColumnName )?
+AlterTableStmt
+         ::= 'ALTER' 'IGNORE'? 'TABLE' TableName AddColumnSpec ( ',' AddColumnSpec )*
+
+TableName ::=
+    Identifier ('.' Identifier)?
+
+AddColumnSpec
+         ::= 'ADD' 'COLUMN' 'IF NOT EXISTS'? ColumnName ColumnType ColumnOption+ ( 'FIRST' | 'AFTER' ColumnName )?
+
+ColumnType
+         ::= NumericType
+           | StringType
+           | DateAndTimeType
+           | 'SERIAL'
+
+ColumnOption
+         ::= 'NOT'? 'NULL'
+           | 'AUTO_INCREMENT'
+           | 'PRIMARY'? 'KEY' ( 'CLUSTERED' | 'NONCLUSTERED' )?
+           | 'UNIQUE' 'KEY'?
+           | 'DEFAULT' ( NowSymOptionFraction | SignedLiteral | NextValueForSequence )
+           | 'SERIAL' 'DEFAULT' 'VALUE'
+           | 'ON' 'UPDATE' NowSymOptionFraction
+           | 'COMMENT' stringLit
+           | ( 'CONSTRAINT' Identifier? )? 'CHECK' '(' Expression ')' ( 'NOT'? ( 'ENFORCED' | 'NULL' ) )?
+           | 'GENERATED' 'ALWAYS' 'AS' '(' Expression ')' ( 'VIRTUAL' | 'STORED' )?
+           | 'REFERENCES' TableName ( '(' IndexPartSpecificationList ')' )? Match? OnDeleteUpdateOpt
+           | 'COLLATE' CollationName
+           | 'COLUMN_FORMAT' ColumnFormat
+           | 'STORAGE' StorageMedia
+           | 'AUTO_RANDOM' ( '(' LengthNum ')' )?
 ```
 
 ## Examples

statistics.md

@@ -481,14 +481,16 @@ You can view the statistics status using the following statements.
 
 You can use the `SHOW STATS_META` statement to view the total number of rows and the number of updated rows.
 
-The syntax of `ShowLikeOrWhereOpt` is as follows:
-
 {{< copyable "sql" >}}
 
 ```sql
-SHOW STATS_META [ShowLikeOrWhere]
+SHOW STATS_META [ShowLikeOrWhere];
 ```
 
+The syntax of `ShowLikeOrWhereOpt` is as follows:
+
+![ShowLikeOrWhereOpt](/media/sqlgram/ShowLikeOrWhereOpt.png)
+
 Currently, the `SHOW STATS_META` statement returns the following 6 columns:
 
 | Column name | Description  |
@@ -508,13 +510,17 @@ Currently, the `SHOW STATS_META` statement returns the following 6 columns:
 
 You can use the `SHOW STATS_HEALTHY` statement to check the health state of tables and roughly estimate the accuracy of the statistics. When `modify_count` >= `row_count`, the health state is 0; when `modify_count` < `row_count`, the health state is (1 - `modify_count`/`row_count`) * 100.
 
-The synopsis of `SHOW STATS_HEALTHY` is:
+The syntax is as follows:
 
-![ShowStatsHealthy](/media/sqlgram/ShowStatsHealthy.png)
+{{< copyable "sql" >}}
+
+```sql
+SHOW STATS_HEALTHY [ShowLikeOrWhere];
+```
 
-and the synopsis of the `ShowLikeOrWhereOpt` part is:
+The synopsis of `SHOW STATS_HEALTHY` is:
 
-![ShowLikeOrWhereOpt](/media/sqlgram/ShowLikeOrWhereOpt.png)
+![ShowStatsHealthy](/media/sqlgram/ShowStatsHealthy.png)
 
 Currently, the `SHOW STATS_HEALTHY` statement returns the following 4 columns:
 

tiflash-deployment-topology.md

@@ -14,10 +14,10 @@ TiFlash is a columnar storage engine, and gradually becomes the standard cluster
 
 | Instance | Count | Physical machine configuration | IP | Configuration |
 | :-- | :-- | :-- | :-- | :-- |
-| TiDB | 3 | 16 VCore 32GB * 1 | 10.0.1.1 <br/> 10.0.1.2 <br/> 10.0.1.3 | Default port <br/> Global directory configuration |
+| TiDB | 3 | 16 VCore 32GB * 1 | 10.0.1.7 <br/> 10.0.1.8 <br/> 10.0.1.9 | Default port <br/> Global directory configuration |
 | PD | 3 | 4 VCore 8GB * 1 | 10.0.1.4 <br/> 10.0.1.5 <br/> 10.0.1.6 | Default port <br/> Global directory configuration |
 | TiKV | 3 | 16 VCore 32GB 2TB (nvme ssd) * 1 | 10.0.1.1 <br/> 10.0.1.2 <br/> 10.0.1.3 | Default port <br/> Global directory configuration |
-| TiFlash | 1 | 32 VCore 64 GB 2TB (nvme ssd) * 1  | 10.0.1.10 | Default port <br/> Global directory configuration |
+| TiFlash | 1 | 32 VCore 64 GB 2TB (nvme ssd) * 1  | 10.0.1.11 | Default port <br/> Global directory configuration |
 | Monitoring & Grafana | 1 | 4 VCore 8GB * 1 500GB (ssd) | 10.0.1.10 | Default port <br/> Global directory configuration |
 
 ### Topology templates