更新时间：2024-05-17 GMT+08:00
分区表相关内置工具函数
前置建表相关信息
- 前置建表：
CREATE TABLE test_range_pt (a INT, b INT, c INT) PARTITION BY RANGE (a) ( PARTITION p1 VALUES LESS THAN (2000), PARTITION p2 VALUES LESS THAN (3000), partition p3 VALUES LESS THAN (4000), partition p4 VALUES LESS THAN (5000), partition p5 VALUES LESS THAN (MAXVALUE) )ENABLE ROW MOVEMENT; - 查看分区表oid
SELECT oid FROM pg_class WHERE relname = 'test_range_pt'; oid ------- 49290 (1 row)
- 查看分区信息
SELECT oid,relname,parttype,parentid,boundaries FROM pg_partition WHERE parentid = 49290; oid | relname | parttype | parentid | boundaries -------+---------------+----------+----------+------------ 49293 | test_range_pt | r | 49290 | 49294 | p1 | p | 49290 | {2000} 49295 | p2 | p | 49290 | {3000} 49296 | p3 | p | 49290 | {4000} 49297 | p4 | p | 49290 | {5000} 49298 | p5 | p | 49290 | {NULL} (6 rows) - 创建索引
CREATE INDEX idx_range_a ON test_range_pt(a) LOCAL; CREATE INDEX --查看分区索引oid SELECT oid FROM pg_class WHERE relname = 'idx_range_a'; oid ------- 90250 (1 row)
- 查看索引分区信息
SELECT oid,relname,parttype,parentid,boundaries,indextblid FROM pg_partition WHERE parentid = 90250; oid | relname | parttype | parentid | boundaries | indextblid -------+----------+----------+----------+------------+------------ 90255 | p5_a_idx | x | 90250 | | 49298 90254 | p4_a_idx | x | 90250 | | 49297 90253 | p3_a_idx | x | 90250 | | 49296 90252 | p2_a_idx | x | 90250 | | 49295 90251 | p1_a_idx | x | 90250 | | 49294 (5 rows)
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)
- pg_partition_size(oid,oid)指定OID代表的分区使用的磁盘空间。其中，第一个oid为表的OID，第二个oid为分区的OID。
SELECT pg_partition_size(49290, 49294); pg_partition_size ------------------- 90112 (1 row)
- pg_partition_size(text, text) 指定名称的分区使用的磁盘空间。其中，第一个text为表名，第二个text为分区名。
SELECT pg_partition_size('test_range_pt', 'p1'); pg_partition_size ------------------- 90112 (1 row)
- pg_partition_indexes_size(oid,oid)指定OID代表的分区的索引使用的磁盘空间。其中，第一个oid为表的OID，第二个oid为分区的OID。
SELECT pg_partition_indexes_size(49290, 49294); pg_partition_indexes_size --------------------------- 204800 (1 row)
- pg_partition_indexes_size(text,text) 指定名称的分区的索引使用的磁盘空间。其中，第一个text为表名，第二个text为分区名。
SELECT pg_partition_indexes_size('test_range_pt', 'p1'); pg_partition_indexes_size --------------------------- 204800 (1 row)
- pg_partition_filenode(partition_oid) 获取到指定分区表的oid所对应的filenode。
SELECT pg_partition_filenode(49294); pg_partition_filenode ----------------------- 49294 (1 row)
父主题： 分区表系统视图&DFX
