PostgreSQL12.5中分區(qū)表的一些操作實例
1、創(chuàng)建一個有DEFAULT的分區(qū)表
1、先創(chuàng)建主表
create table tbl_log
(
id serial,
create_time timestamp(0) without time zone,
remark char(1)
) PARTITION BY RANGE (create_time);
#因為是serial類型,自增的所以會自動創(chuàng)建一個序列
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、如果沒有創(chuàng)建分區(qū)就直接插入數據會報錯
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 00:00:00). postgres=#
3、創(chuàng)建分區(qū)
#包括左邊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、查看分區(qū)情況
postgres=# select * from tbl_log;
id | create_time | remark
----+---------------------+--------
1 | 2018-02-01 00:00:00 | a
2 | 2018-03-01 00:00:00 | b
3 | 2018-04-01 00:00:00 | d
4 | 2020-07-01 00:00:00 | 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 00:00:00 | a
(1 row)
postgres=# select * from tbl_log_p201803;
id | create_time | remark
----+---------------------+--------
2 | 2018-03-01 00:00:00 | b
(1 row)
postgres=# select * from tbl_log_default;
id | create_time | remark
----+---------------------+--------
3 | 2018-04-01 00:00:00 | d
4 | 2020-07-01 00:00:00 | c
(2 rows)
postgres=#
2、有default 分區(qū),再加分區(qū)
因為有default 分區(qū),再加分區(qū),所以會報錯
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
解決辦法:
以上添加分區(qū)報錯,需要解綁default分區(qū),之后再添加,如下
1、解綁Default分區(qū)
postgres=# ALTER TABLE tbl_log DETACH PARTITION tbl_log_default; ALTER TABLE
2、創(chuàng)建想要的分區(qū)
postgres=# CREATE TABLE tbl_log_p201804 PARTITION OF tbl_log FOR VALUES FROM ('2018-04-01') TO ('2018-05-01');
CREATE TABLE
3、分區(qū)創(chuàng)建成功,分區(qū)創(chuàng)建之后需把DEFAULT分區(qū)連接。
連接DEFAULT分區(qū)報錯,如下:
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 00:00:00, c).
因為tbl_log_default分區(qū)內有2018-04-01的數據,把這個數據從tbl_log_default中導出到對應的分區(qū),并清理tbl_log_default中的對應的數據
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、再次連接DEFAULT分區(qū)成功
postgres=# ALTER TABLE tbl_log ATTACH PARTITION tbl_log_default DEFAULT; ALTER TABLE
3、沒有default的分區(qū)
創(chuàng)建沒有default的分區(qū),當插入的數據超過規(guī)劃好的分區(qū)的時候會報錯
1、創(chuàng)建1月份分區(qū)
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月的數據就會報錯
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 00:00:00).
4、給分區(qū)表ddl
4.1、在原來沒有主鍵的分區(qū)表加主鍵
結論:
1、在主表加主鍵,主鍵為僅僅想要的主鍵,會報錯,需要用想要的主鍵+分區(qū)鍵組合為主鍵
2、分區(qū)表可以單獨添加主鍵
1.1、在主表加主鍵,主鍵為僅僅想要的主鍵,報錯如下 must include all partitioning columns
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、在主表添加主鍵需要是想要的主鍵+分區(qū)鍵
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 00:00:00') TO ('2018-02-01 00:00:00')
Indexes:
"tbl_log_p201801_pkey" PRIMARY KEY, btree (id, create_time)
1.3、可以給分區(qū)表單獨添加主鍵
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 00:00:00') TO ('2018-02-01 00:00:00')
Indexes:
"tbl_log_p201801_pkey" PRIMARY KEY, btree (id)
postgres=#
4.2、創(chuàng)建分區(qū)表時,就指定主鍵
主鍵不包括分區(qū)鍵,報錯提示must include all partitioning columns
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.
修改語句,添加分區(qū)鍵也為主鍵,創(chuàng)建成功
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、分區(qū)表加字段,修改字段
1、加字段,可以成功添加,在主表加字段,分區(qū)表會自動添加
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 00:00:00') TO ('2018-02-01 00:00:00')
2、直接在分區(qū)表加字段會報錯
postgres=# alter table tbl_log_p201801 add name2 varchar(2); ERROR: cannot add column to a partition
3、修改字段
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 00:00:00') TO ('2018-02-01 00:00:00')
Indexes:
"tbl_log_p201801_pkey" PRIMARY KEY, btree (id, create_time)
postgres=#
總結
到此這篇關于PostgreSQL12.5中分區(qū)表的一些操作的文章就介紹到這了,更多相關pg12.5分區(qū)表操作內容請搜索腳本之家以前的文章或繼續(xù)瀏覽下面的相關文章希望大家以后多多支持腳本之家!
相關文章
在PostgreSQL中使用ltree處理層次結構數據的方法
這篇文章主要介紹了在PostgreSQL中使用ltree處理層次結構數據,本文給大家介紹的非常詳細,對大家的學習或工作具有一定的參考借鑒價值,需要的朋友可以參考下2021-03-03
如何將postgresql數據庫表內數據導出為excel格式(推薦)
這篇文章主要介紹了如何將postgresql數據庫表內數據導出為excel格式(推薦),本文給大家介紹的非常詳細,對大家的學習或工作具有一定的參考借鑒價值,需要的朋友可以參考下2021-03-03

