forked from pingcap/docs
-
Notifications
You must be signed in to change notification settings - Fork 0
Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
Merge remote-tracking branch 'upstream/master'
- Loading branch information
Showing
5 changed files
with
134 additions
and
33 deletions.
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,88 @@ | ||
| --- | ||
| title: ADMIN ALTER DDL JOBS | ||
| summary: An overview of the usage of `ADMIN ALTER DDL JOBS` for the TiDB database. | ||
| --- | ||
|
|
||
| # ADMIN ALTER DDL JOBS | ||
|
|
||
| The `ADMIN ALTER DDL JOBS` statement allows you to modify the parameter of a single running DDL job. For example: | ||
|
|
||
| ```sql | ||
| ADMIN ALTER DDL JOBS 101 THREAD = 8; | ||
| ``` | ||
|
|
||
| - `101`: indicates the ID of the DDL job. You can obtain the ID by executing [`ADMIN SHOW DDL JOBS`](/sql-statements/sql-statement-admin-show-ddl.md). | ||
| - `THREAD`: indicates the concurrency of the DDL job. You can configure its initial value using the system variable [`tidb_ddl_reorg_worker_cnt`](/system-variables.md#tidb_ddl_reorg_worker_cnt). | ||
|
|
||
| The DDL job types supported by the `ADMIN ALTER DDL JOBS` statement include `ADD INDEX`, `MODIFY COLUMN`, and `REORGANIZE PARTITION`. For other DDL job types, executing `ADMIN ALTER DDL JOBS` returns the `unsupported DDL operation` error. | ||
|
|
||
| Currently, you can only modify the parameters of a single DDL job by executing `ADMIN ALTER DDL JOBS`. Modifying the parameters of multiple DDL job IDs at the same time is not supported. | ||
|
|
||
| The following are the supported parameters for different DDL jobs and their corresponding system variables: | ||
|
|
||
| - `ADD INDEX`: | ||
| - `THREAD`: the concurrency of the DDL job. The initial value is set by `tidb_ddl_reorg_worker_cnt`. | ||
| - `BATCH_SIZE`: the batch size. The initial value is set by [`tidb_ddl_reorg_batch_size`](/system-variables.md#tidb_ddl_reorg_batch_size). | ||
| - `MAX_WRITE_SPEED`: the maximum bandwidth limit for importing index records into each TiKV. The initial value is set by [`tidb_ddl_reorg_max_write_speed`](/system-variables.md#tidb_ddl_reorg_max_write_speed-new-in-v850). | ||
|
|
||
| Currently, the preceding parameters only work for `ADD INDEX` jobs that are submitted and running after [`tidb_enable_dist_task`](/system-variables.md#tidb_enable_dist_task-new-in-v710) is disabled. | ||
|
|
||
| - `MODIFY COLUMN`: | ||
| - `THREAD`: the concurrency of the DDL job. The initial value is set by `tidb_ddl_reorg_worker_cnt`. | ||
| - `BATCH_SIZE`: the batch size. The initial value is set by `tidb_ddl_reorg_batch_size`. | ||
|
|
||
| - `REORGANIZE PARTITION`: | ||
| - `THREAD`: the concurrency of the DDL job. The initial value is set by `tidb_ddl_reorg_worker_cnt`. | ||
| - `BATCH_SIZE`: the batch size. The initial value is set by `tidb_ddl_reorg_batch_size`. | ||
|
|
||
| The value ranges of the preceding parameters are consistent with those of the corresponding system variables. | ||
|
|
||
| `ADMIN ALTER DDL JOBS` takes effect only on running DDL jobs. If the DDL job does not exist or has already completed, executing this statement returns the `ddl job is not running` error. | ||
|
|
||
| The following are some examples of this statement: | ||
|
|
||
| ```sql | ||
| ADMIN ALTER DDL JOBS 101 THREAD = 8; | ||
| ADMIN ALTER DDL JOBS 101 BATCH_SIZE = 256; | ||
| ADMIN ALTER DDL JOBS 101 MAX_WRITE_SPEED = '200MiB'; | ||
| ADMIN ALTER DDL JOBS 101 THREAD = 8, BATCH_SIZE = 256; | ||
| ``` | ||
|
|
||
| To view the current parameter values for a specific DDL job, you can execute `ADMIN SHOW DDL JOBS`. The results are displayed in the `COMMENTS` column: | ||
|
|
||
| ```sql | ||
| ADMIN SHOW DDL JOBS 1; | ||
| ``` | ||
|
|
||
| ``` | ||
| +--------+---------+------------+-----------+--------------+-----------+----------+-----------+----------------------------+----------------------------+----------------------------+--------+-----------------------+ | ||
| | JOB_ID | DB_NAME | TABLE_NAME | JOB_TYPE | SCHEMA_STATE | SCHEMA_ID | TABLE_ID | ROW_COUNT | CREATE_TIME | START_TIME | END_TIME | STATE | COMMENTS | | ||
| +--------+---------+------------+-----------+--------------+-----------+----------+-----------+----------------------------+----------------------------+----------------------------+--------+-----------------------+ | ||
| | 124 | test | t | add index | public | 2 | 122 | 3 | 2024-11-15 11:17:06.213000 | 2024-11-15 11:17:06.213000 | 2024-11-15 11:17:08.363000 | synced | ingest, DXF, thread=8 | | ||
| +--------+---------+------------+-----------+--------------+-----------+----------+-----------+----------------------------+----------------------------+----------------------------+--------+-----------------------+ | ||
| 1 row in set (0.01 sec) | ||
| ``` | ||
|
|
||
| ## Synopsis | ||
|
|
||
| ```ebnf+diagram | ||
| AdminAlterDDLStmt ::= | ||
| 'ADMIN' 'ALTER' 'DDL' 'JOBS' Int64Num AlterJobOptionList | ||
| AlterJobOptionList ::= | ||
| AlterJobOption ( ',' AlterJobOption )* | ||
| AlterJobOption ::= | ||
| identifier "=" SignedLiteral | ||
| ``` | ||
|
|
||
| ## MySQL compatibility | ||
|
|
||
| This statement is a TiDB extension to MySQL syntax. | ||
|
|
||
| ## See also | ||
|
|
||
| * [`ADMIN SHOW DDL [JOBS|QUERIES]`](/sql-statements/sql-statement-admin-show-ddl.md) | ||
| * [`ADMIN CANCEL DDL`](/sql-statements/sql-statement-admin-cancel-ddl.md) | ||
| * [`ADMIN PAUSE DDL`](/sql-statements/sql-statement-admin-pause-ddl.md) | ||
| * [`ADMIN RESUME DDL`](/sql-statements/sql-statement-admin-resume-ddl.md) |
Oops, something went wrong.