云数据库 GAUSSDB-分区表相关内置工具函数:工具函数示例

时间：2024-11-02 18:49:17

云数据库 GAUSSDB 分区表系统视图&DFX

工具函数示例

pg_get_tabledef获取分区表的定义，入参可以为表的oid或者表名。

SELECT pg_get_tabledef('test_range_pt');
                          pg_get_tabledef                           
--------------------------------------------------------------------
 SET search_path = public;                                         +
 CREATE TABLE test_range_pt (                                      +
     a integer,                                                    +
     b integer,                                                    +
     c integer                                                     +
 )                                                                 +
 WITH (orientation=row, compression=no)                            +
 PARTITION BY RANGE (a)                                            +
 (                                                                 +
     PARTITION p1 VALUES LESS THAN (2000) TABLESPACE pg_default,   +
     PARTITION p2 VALUES LESS THAN (3000) TABLESPACE pg_default,   +
     PARTITION p3 VALUES LESS THAN (4000) TABLESPACE pg_default,   +
     PARTITION p4 VALUES LESS THAN (5000) TABLESPACE pg_default,   +
     PARTITION p5 VALUES LESS THAN (MAXVALUE) TABLESPACE pg_default+
 )                                                                 +
 ENABLE ROW MOVEMENT;
(1 row)

pg_stat_get_partition_tuples_hot_updated返回给定分区id的分区热更新元组数的统计。

在分区p1中插入10条数据并更新，统计分区p1的热更新元组数。

INSERT INTO test_range_pt VALUES(generate_series(1,10),1,1);
INSERT 0 10
SELECT pg_stat_get_partition_tuples_hot_updated(49294);
pg_stat_get_partition_tuples_hot_updated
------------------------------------------
0
(1 row)
UPDATE test_range_pt SET b = 2;
UPDATE 10
SELECT pg_stat_get_partition_tuples_hot_updated(49294);
pg_stat_get_partition_tuples_hot_updated
------------------------------------------
10
(1 row)

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