Important

You are viewing the documentation of an older version of the TiDB database (TiDB v5.4).

It is recommended that you use the latest LTS version of the TiDB database.

SHOW PLACEMENT FOR

Warning

Placement Rules in SQL is an experimental feature. The syntax might change before its GA, and there might also be bugs.

If you understand the risks, you can enable this experiment feature by executing SET GLOBAL tidb_enable_alter_placement = 1;.

SHOW PLACEMENT FOR summarizes all placement options from direct placement and placement policies, and presents them in the canonical form for a specific table, database schema, or partition.

Synopsis

ShowStmt
PLACEMENTFORShowPlacementTarget
ShowPlacementTarget
DatabaseSymDBNameTABLETableNameTABLETableNamePARTITIONIdentifier

Examples

CREATE PLACEMENT POLICY p1 PRIMARY_REGION="us-east-1" REGIONS="us-east-1,us-west-1" FOLLOWERS=4;
use test;
ALTER DATABASE test PLACEMENT POLICY=p1;
CREATE TABLE t1 (a INT);
CREATE TABLE t2 (a INT) PRIMARY_REGION="us-east-1" REGIONS="us-east-1,us-west-1" FOLLOWERS=4;
SHOW PLACEMENT FOR DATABASE test;
SHOW PLACEMENT FOR TABLE t1;
SHOW CREATE TABLE t1\G
SHOW PLACEMENT FOR TABLE t2;
CREATE TABLE t3 (a INT) PARTITION BY RANGE (a) (PARTITION p1 VALUES LESS THAN (10), PARTITION p2 VALUES LESS THAN (20) FOLLOWERS=4);
SHOW PLACEMENT FOR TABLE t3 PARTITION p1;
SHOW PLACEMENT FOR TABLE t3 PARTITION p2;
Query OK, 0 rows affected (0.02 sec)

Query OK, 0 rows affected (0.00 sec)

Query OK, 0 rows affected (0.00 sec)

Query OK, 0 rows affected (0.01 sec)

+---------------+----------------------------------------------------------------------+------------------+
| Target        | Placement                                                            | Scheduling_State |
+---------------+----------------------------------------------------------------------+------------------+
| DATABASE test | PRIMARY_REGION="us-east-1" REGIONS="us-east-1,us-west-1" FOLLOWERS=4 | INPROGRESS       |
+---------------+----------------------------------------------------------------------+------------------+
1 row in set (0.00 sec)

+---------------+-------------+------------------+
| Target        | Placement   | Scheduling_State |
+---------------+-------------+------------------+
| TABLE test.t1 | FOLLOWERS=4 | INPROGRESS       |
+---------------+-------------+------------------+
1 row in set (0.00 sec)

*************************** 1. row ***************************
       Table: t1
Create Table: CREATE TABLE `t1` (
  `a` int(11) DEFAULT NULL
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin /*T![placement] PLACEMENT POLICY=`p1` */
1 row in set (0.00 sec)

+---------------+----------------------------------------------------------------------+------------------+
| Target        | Placement                                                            | Scheduling_State |
+---------------+----------------------------------------------------------------------+------------------+
| TABLE test.t2 | PRIMARY_REGION="us-east-1" REGIONS="us-east-1,us-west-1" FOLLOWERS=4 | INPROGRESS       |
+---------------+----------------------------------------------------------------------+------------------+
1 row in set (0.00 sec)

Query OK, 0 rows affected (0.14 sec)

+----------------------------+-----------------------------------------------------------------------+------------------+
| Target                     | Placement                                                             | Scheduling_State |
+----------------------------+-----------------------------------------------------------------------+------------------+
| TABLE test.t3 PARTITION p1 | PRIMARY_REGION="us-east-1" REGIONS="us-east-1,,us-west-1" FOLLOWERS=4 | INPROGRESS       |
+----------------------------+-----------------------------------------------------------------------+------------------+
1 row in set (0.00 sec)

+----------------------------+-------------+------------------+
| Target                     | Placement   | Scheduling_State |
+----------------------------+-------------+------------------+
| TABLE test.t3 PARTITION p2 | FOLLOWERS=4 | INPROGRESS       |
+----------------------------+-------------+------------------+
1 row in set (0.00 sec)

MySQL compatibility

This statement is a TiDB extension to MySQL syntax.

See also

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