PLACEMENT_POLICIES

PLACEMENT_POLICIES 表展示所有放置策略 (placement policy) 的信息,见 Placement Rules in SQL

USE information_schema; DESC placement_policies;
+----------------------+---------------+------+-----+---------+-------+ | Field | Type | Null | Key | Default | Extra | +----------------------+---------------+------+-----+---------+-------+ | POLICY_ID | bigint(64) | NO | | <null> | | | CATALOG_NAME | varchar(512) | NO | | <null> | | | POLICY_NAME | varchar(64) | NO | | <null> | | | PRIMARY_REGION | varchar(1024) | YES | | <null> | | | REGIONS | varchar(1024) | YES | | <null> | | | CONSTRAINTS | varchar(1024) | YES | | <null> | | | LEADER_CONSTRAINTS | varchar(1024) | YES | | <null> | | | FOLLOWER_CONSTRAINTS | varchar(1024) | YES | | <null> | | | LEARNER_CONSTRAINTS | varchar(1024) | YES | | <null> | | | SCHEDULE | varchar(20) | YES | | <null> | | | FOLLOWERS | bigint(64) | YES | | <null> | | | LEARNERS | bigint(64) | YES | | <null> | | +----------------------+---------------+------+-----+---------+-------+ 12 rows in set (0.00 sec)

示例

PLACEMENT_POLICIES 表只展示放置策略 (placement policy) 的信息。如需查看所有信息的规范版本(放置策略,以及绑定放置策略的对象),请改用 SHOW PLACEMENT 语句:

CREATE TABLE t1 (a INT); CREATE PLACEMENT POLICY p1 primary_region="us-east-1" regions="us-east-1"; CREATE TABLE t3 (a INT) PLACEMENT POLICY=p1; SHOW PLACEMENT; -- 显示所有信息,包含 t3。 SELECT * FROM information_schema.placement_policies; -- 只显示放置策略,不包含 t3。
Query OK, 0 rows affected (0.09 sec) Query OK, 0 rows affected (0.11 sec) Query OK, 0 rows affected (0.08 sec) +---------------+------------------------------------------------+------------------+ | Target | Placement | Scheduling_State | +---------------+------------------------------------------------+------------------+ | POLICY p1 | PRIMARY_REGION="us-east-1" REGIONS="us-east-1" | NULL | | TABLE test.t3 | PRIMARY_REGION="us-east-1" REGIONS="us-east-1" | SCHEDULED | +---------------+------------------------------------------------+------------------+ 2 rows in set (0.00 sec) +-----------+--------------+-------------+----------------+-----------+-------------+--------------------+----------------------+---------------------+----------+-----------+----------+ | POLICY_ID | CATALOG_NAME | POLICY_NAME | PRIMARY_REGION | REGIONS | CONSTRAINTS | LEADER_CONSTRAINTS | FOLLOWER_CONSTRAINTS | LEARNER_CONSTRAINTS | SCHEDULE | FOLLOWERS | LEARNERS | +-----------+--------------+-------------+----------------+-----------+-------------+--------------------+----------------------+---------------------+----------+-----------+----------+ | 1 | def | p1 | us-east-1 | us-east-1 | | | | | | 2 | 0 | +-----------+--------------+-------------+----------------+-----------+-------------+--------------------+----------------------+---------------------+----------+-----------+----------+ 1 rows in set (0.00 sec)