分区(分区子表、子分区)
分区表中实际保存数据的表,对应的entry通常保存在pg_partition中,各个子分区的parentid作为外键关联其分区母表在pg_class表中的OID列。
示例:t1_hash为一个分区表:
gaussdb=# CREATE TABLE t1_hash (c1 INT, c2 INT, c3 INT)
PARTITION BY HASH(c1)
(
    PARTITION p0,
    PARTITION p1,
    PARTITION p2,
    PARTITION p3,
    PARTITION p4,
    PARTITION p5,
    PARTITION p6,
    PARTITION p7,
    PARTITION p8,
    PARTITION p9
);
--查询t1_hash分区类型。
gaussdb=# SELECT oid, relname, parttype FROM pg_class WHERE relname = 't1_hash';
oid  | relname | parttype
-------+---------+----------
16685 | t1_hash | p      
(1 row)
--查询t1_hash的分区信息。
gaussdb=# SELECT oid, relname, parttype, parentid FROM pg_partition WHERE parentid = 16685;
oid  | relname | parttype | parentid
-------+---------+----------+----------
16688 | t1_hash | r        |    16685
16689 | p0      | p        |    16685
16690 | p1      | p        |    16685
16691 | p2      | p        |    16685
16692 | p3      | p        |    16685
16693 | p4      | p        |    16685
16694 | p5      | p        |    16685
16695 | p6      | p        |    16685
16696 | p7      | p        |    16685
16697 | p8      | p        |    16685
16698 | p9      | p        |    16685
(11 rows)
--删除t1_hash
gaussdb=# DROP TABLE t1_hash; 
                    
                     
                    
                 
                    
                 
 
         
                
            
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浙公网安备 33010602011771号