1、创建一个有DEFAULT的分区表
1、先创建主表
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create table tbl_log ( id serial, create_time timestamp (0) without time zone, remark char (1) ) PARTITION BY RANGE (create_time); #因为是serial类型，自增的所以会自动创建一个序列 postgres=# \d List of relations Schema | Name | Type | Owner --------+----------------+-------------------+---------- public | tbl_log | partitioned table | postgres public | tbl_log_id_seq | sequence | postgres (7 rows ) |
2、如果没有创建分区就直接插入数据会报错
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postgres=# INSERT INTO tbl_log(id, create_time, remark) VALUES (1, '2018-02-01' , 'a' ); ERROR: no partition of relation "tbl_log" found for row DETAIL: Partition key of the failing row contains (create_time) = (2018-02-01 0). postgres=# |
3、创建分区
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#包括左边1.1，不包括2.1 CREATE TABLE tbl_log_p201801 PARTITION OF tbl_log FOR VALUES FROM ( '2018-01-01' ) TO ( '2018-02-01' ); CREATE TABLE tbl_log_p201802 PARTITION OF tbl_log FOR VALUES FROM ( '2018-02-01' ) TO ( '2018-03-01' ); CREATE TABLE tbl_log_p201803 PARTITION OF tbl_log FOR VALUES FROM ( '2018-03-01' ) TO ( '2018-04-01' ); CREATE TABLE tbl_log_default PARTITION OF tbl_log DEFAULT ; INSERT INTO tbl_log(id, create_time, remark) VALUES (1, '2018-02-01' , 'a' ); INSERT INTO tbl_log(id, create_time, remark) VALUES (2, '2018-03-01' , 'b' ); INSERT INTO tbl_log(id, create_time, remark) VALUES (3, '2018-04-01' , 'd' ); INSERT INTO tbl_log(id, create_time, remark) VALUES (4, '2020-07-01' , 'c' ); |
4、查看分区情况
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postgres=# select * from tbl_log; id | create_time | remark ----+---------------------+-------- 1 | 2018-02-01 0 | a 2 | 2018-03-01 0 | b 3 | 2018-04-01 0 | d 4 | 2020-07-01 0 | c (4 rows ) postgres=# select * from tbl_log_p201801; id | create_time | remark ----+-------------+-------- (0 rows ) postgres=# select * from tbl_log_p201802; id | create_time | remark ----+---------------------+-------- 1 | 2018-02-01 0 | a (1 row) postgres=# select * from tbl_log_p201803; id | create_time | remark ----+---------------------+-------- 2 | 2018-03-01 0 | b (1 row)
postgres=# select * from tbl_log_default; id | create_time | remark ----+---------------------+-------- 3 | 2018-04-01 0 | d 4 | 2020-07-01 0 | c (2 rows ) postgres=# |
2、有default 分区，再加分区
因为有default 分区，再加分区，所以会报错
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postgres=# CREATE TABLE tbl_log_p201804 PARTITION OF tbl_log FOR VALUES FROM ( '2018-04-01' ) TO ( '2018-05-01' ); ERROR: updated partition constraint for default partition "tbl_log_default" would be violated by some row |
解决办法：
以上添加分区报错，需要解绑default分区，之后再添加，如下
1、解绑Default分区
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postgres=# ALTER TABLE tbl_log DETACH PARTITION tbl_log_default; ALTER TABLE |
2、创建想要的分区
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postgres=# CREATE TABLE tbl_log_p201804 PARTITION OF tbl_log FOR VALUES FROM ( '2018-04-01' ) TO ( '2018-05-01' ); CREATE TABLE |
3、分区创建成功，分区创建之后需把DEFAULT分区连接。
连接DEFAULT分区报错，如下:
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postgres=# ALTER TABLE tbl_log ATTACH PARTITION tbl_log_default DEFAULT ; ERROR: partition constraint is violated by some row postgres=# INSERT INTO tbl_log_p201804 SELECT * FROM tbl_log_default; ERROR: new row for relation "tbl_log_p201804" violates partition constraint DETAIL: Failing row contains (4, 2020-07-01 0, c). |
因为tbl_log_default分区内有2018-04-01的数据，把这个数据从tbl_log_default中导出到对应的分区，并清理tbl_log_default中的对应的数据
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postgres=# INSERT INTO tbl_log_p201804 SELECT * FROM tbl_log_default where create_time>= '2018-04-01' and create_time< '2018-05-01' ; INSERT 0 1 postgres=# delete from tbl_log_default where create_time>= '2018-04-01' and create_time< '2018-05-01' ; DELETE 1 |
4、再次连接DEFAULT分区成功
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postgres=# ALTER TABLE tbl_log ATTACH PARTITION tbl_log_default DEFAULT ; ALTER TABLE |
3、没有default的分区
创建没有default的分区，当插入的数据超过规划好的分区的时候会报错
1、创建1月份分区
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create table tbl_log2 ( id serial, create_time timestamp (0) without time zone, remark char (1) ) PARTITION BY RANGE (create_time); CREATE TABLE tbl_log2_p201801 PARTITION OF tbl_log2 FOR VALUES FROM ( '2018-01-01' ) TO ( '2018-02-01' ); |
插入2月的数据就会报错
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postgres=# INSERT INTO tbl_log2(id, create_time, remark) VALUES (1, '2018-01-01' , 'a' ); INSERT 0 1 postgres=# INSERT INTO tbl_log2(id, create_time, remark) VALUES (1, '2018-02-01' , 'a' ); ERROR: no partition of relation "tbl_log2" found for row DETAIL: Partition key of the failing row contains (create_time) = (2018-02-01 0). |
4、给分区表ddl
4.1、在原来没有主键的分区表加主键
结论：
1、在主表加主键，主键为仅仅想要的主键，会报错，需要用想要的主键+分区键组合为主键
2、分区表可以单独添加主键
1.1、在主表加主键，主键为仅仅想要的主键，报错如下 must include all partitioning columns
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postgres=# alter table tbl_log add primary key (id); ERROR: unique constraint on partitioned table must include all partitioning columns DETAIL: PRIMARY KEY constraint on table "tbl_log" lacks column "create_time" which is part of the partition key . postgres=# alter table tbl_log add primary key (id) |
1.2、在主表添加主键需要是想要的主键+分区键
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postgres=# alter table tbl_log add primary key (id,create_time); ALTER TABLE postgres=# \d tbl_log Partitioned table "public.tbl_log" Column | Type | Collation | Nullable | Default -------------+--------------------------------+-----------+----------+------------------------------------- id | integer | | not null | nextval( 'tbl_log_id_seq' ::regclass) create_time | timestamp (0) without time zone | | not null | remark | character (1) | | | name | character varying (2) | | | Partition key : RANGE (create_time) Indexes: "tbl_log_pkey" PRIMARY KEY , btree (id, create_time) Number of partitions: 5 (Use \d+ to list them.) postgres=# \d tbl_log_p201801 Table "public.tbl_log_p201801" Column | Type | Collation | Nullable | Default -------------+--------------------------------+-----------+----------+------------------------------------- id | integer | | not null | nextval( 'tbl_log_id_seq' ::regclass) create_time | timestamp (0) without time zone | | not null | remark | character (1) | | | name | character varying (2) | | | Partition of : tbl_log FOR VALUES FROM ( '2018-01-01 0' ) TO ( '2018-02-01 0' ) Indexes: "tbl_log_p201801_pkey" PRIMARY KEY , btree (id, create_time) |
1.3、可以给分区表单独添加主键
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postgres=# alter table tbl_log_p201801 add primary key (id); ALTER TABLE postgres=# \d tbl_log_p201801 Table "public.tbl_log_p201801" Column | Type | Collation | Nullable | Default -------------+--------------------------------+-----------+----------+------------------------------------- id | integer | | not null | nextval( 'tbl_log_id_seq' ::regclass) create_time | timestamp (0) without time zone | | | remark | character (1) | | | name | character varying (2) | | | Partition of : tbl_log FOR VALUES FROM ( '2018-01-01 0' ) TO ( '2018-02-01 0' ) Indexes: "tbl_log_p201801_pkey" PRIMARY KEY , btree (id) postgres=# |
4.2、创建分区表时，就指定主键
主键不包括分区键，报错提示must include all partitioning columns
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create table tbl_log2 ( id int , create_time timestamp (0) without time zone, remark char (1), primary key (id) ); ERROR: unique constraint on partitioned table must include all partitioning columns DETAIL: PRIMARY KEY constraint on table "tbl_log2" lacks column "create_time" which is part of the partition key . |
修改语句，添加分区键也为主键，创建成功
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create table tbl_log2 ( id int , create_time timestamp (0) without time zone, remark char (1), primary key (id,create_time) ) PARTITION BY RANGE (create_time); CREATE TABLE |
4.3、分区表加字段，修改字段
1、加字段，可以成功添加，在主表加字段，分区表会自动添加
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postgres=# alter table tbl_log add name varchar (2); ALTER TABLE postgres=# \d tbl_log; Partitioned table "public.tbl_log" Column | Type | Collation | Nullable | Default -------------+--------------------------------+-----------+----------+------------------------------------- id | integer | | not null | nextval( 'tbl_log_id_seq' ::regclass) create_time | timestamp (0) without time zone | | | remark | character (1) | | | name | character varying (2) | | | Partition key : RANGE (create_time) Number of partitions: 5 (Use \d+ to list them.) postgres=# \d tbl_log_p201801; Table "public.tbl_log_p201801" Column | Type | Collation | Nullable | Default -------------+--------------------------------+-----------+----------+------------------------------------- id | integer | | not null | nextval( 'tbl_log_id_seq' ::regclass) create_time | timestamp (0) without time zone | | | remark | character (1) | | | name | character varying (2) | | | Partition of : tbl_log FOR VALUES FROM ( '2018-01-01 0' ) TO ( '2018-02-01 0' ) |
2、直接在分区表加字段会报错
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postgres=# alter table tbl_log_p201801 add name2 varchar (2); ERROR: cannot add column to a partition |
3、修改字段
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postgres=# alter table tbl_log alter column remark type varchar (10); ALTER TABLE postgres=# \d tbl_log; Partitioned table "public.tbl_log" Column | Type | Collation | Nullable | Default -------------+--------------------------------+-----------+----------+------------------------------------- id | integer | | not null | nextval( 'tbl_log_id_seq' ::regclass) create_time | timestamp (0) without time zone | | not null | remark | character varying (10) | | | name | character varying (2) | | | Partition key : RANGE (create_time) Indexes: "tbl_log_pkey" PRIMARY KEY , btree (id, create_time) Number of partitions: 5 (Use \d+ to list them.) postgres=# \d tbl_log_p201801 Table "public.tbl_log_p201801" Column | Type | Collation | Nullable | Default -------------+--------------------------------+-----------+----------+------------------------------------- id | integer | | not null | nextval( 'tbl_log_id_seq' ::regclass) create_time | timestamp (0) without time zone | | not null | remark | character varying (10) | | | name | character varying (2) | | | Partition of : tbl_log FOR VALUES FROM ( '2018-01-01 0' ) TO ( '2018-02-01 0' ) Indexes: "tbl_log_p201801_pkey" PRIMARY KEY , btree (id, create_time) postgres=# |
总结
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原文链接：https://blog.csdn.net/weixin_42583514/article/details/123063420
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