postgresql表分区的简单介绍

PostgreSQL走分区查询问题

PostgreSQL安装:一、windows下安装过程 安装介质:postgresql-9.1.3-1-windows.exe(46M),安装过程非常简单,过程如下: 1、开始安装: 2、选择程序安装目录: 注:安装 PostgreSQL 的分区最好是 NTFS 格式的。PostgreSQL 首要任务是要保证数

成都创新互联公司是一家专注于网站设计制作、网站设计与策划设计,绩溪网站建设哪家好?成都创新互联公司做网站,专注于网站建设十载,网设计领域的专业建站公司;建站业务涵盖:绩溪等地区。绩溪做网站价格咨询:028-86922220

PostgreSQL Partition

create_range_partitions

select create_range_partitions('trip_agg_data'::regclass,'time_key',0::bigint,1::bigint,0,false) ;

trip_agg_data --主表OID

time_key --分区列名,必须有not null约束

0::bigint: --起始值 bigint取决于time_key 类型

1::bigint --间隔值 必须大于0

0 --分区个数

false --不立即迁移数据

add_range_partition

select add_range_partition('trip_agg_data'::REGCLASS,0,2019010100,'trip_agg_data_lt_20190101');

2019010100 不能超过time_key类型的最大值

partition_table_concurrently

select partition_table_concurrently ('trip_agg_data_tim'::regclass,10000, 1.0);

迁移数据到子表

10000 --一个事务批量迁移多少记录

1.0 --获得行锁失败时,休眠多久再次获取,重试60次退出任务

pathman_concurrent_part_tasks

select * from pathman_concurrent_part_tasks;

查看数据迁移进度

disable_pathman_for

select disable_pathman_for('trip_agg_data_tim'::regclass);

禁用分区

drop_range_partition

SELECT drop_range_partition(partition, false) /* move data to parent */

FROM pathman_partition_list WHERE parent = 'trip_agg_data'::regclass

and partition = 'trip_agg_data_greater_20200101'::regclass

删除某个分区表

pathman_partition_list

select * from pathman_partition_list;

查看所有分区表信息

set_enable_parent

select set_enable_parent('trip_agg_data'::regclass,false);

禁用主表

split_range_partition

分裂范围分区

merge_range_partitions

合并范围分区

append_range_partition

向后添加范围分区

prepend_range_partition

向前添加范围分区

drop_range_partition

drop_range_partition(partition TEXT, -- 分区名称

delete_data BOOLEAN DEFAULT TRUE) -- 是否删除分区数据,如果false,表示分区数据迁移到主表

drop_partitions

drop_partitions(parent REGCLASS,

delete_data BOOLEAN DEFAULT FALSE)

attach_range_partition

attach_range_partition(relation REGCLASS, -- 主表OID

partition REGCLASS, -- 分区表OID

start_value ANYELEMENT, -- 起始值

end_value ANYELEMENT) -- 结束值

detach_range_partition

detach_range_partition(partition REGCLASS) -- 指定分区名,转换为普通表

-- 1, create table trip_agg_data_2019

create table trip_agg_data_2019 as select * from trip_agg_data where 1=0;

alter table trip_agg_data_2019 alter column time_key set not null;

-- 2, create_range_partition

select create_range_partitions('trip_agg_data_2019'::regclass,'time_key',0::bigint,1::bigint,0,false) ;

-- 3, detach_range_partition for trip_agg_data'

select detach_range_partition('trip_agg_data_20190101');

select detach_range_partition('trip_agg_data_20190201');

select detach_range_partition('trip_agg_data_20190301');

select detach_range_partition('trip_agg_data_20190401');

select detach_range_partition('trip_agg_data_20190501');

select detach_range_partition('trip_agg_data_20190601');

select detach_range_partition('trip_agg_data_20190701');

select detach_range_partition('trip_agg_data_20190801');

select detach_range_partition('trip_agg_data_20190901');

select detach_range_partition('trip_agg_data_20191001');

select detach_range_partition('trip_agg_data_20191101');

select detach_range_partition('trip_agg_data_20191201');

-- 4, add_range_partition for trip_agg_data'

select add_range_partition('trip_agg_data'::REGCLASS,2019010100,2020010100,'trip_agg_data_20190101_20200101');

-- 5, attach_range_partition for trip_agg_data_2019

select attach_range_partition('trip_agg_data_2019'::REGCLASS,'trip_agg_data_20190101',2019010100,2019020100);

select attach_range_partition('trip_agg_data_2019'::REGCLASS,'trip_agg_data_20190201',2019020100,2019030100);

select attach_range_partition('trip_agg_data_2019'::REGCLASS,'trip_agg_data_20190301',2019030100,2019040100);

select attach_range_partition('trip_agg_data_2019'::REGCLASS,'trip_agg_data_20190401',2019040100,2019050100);

select attach_range_partition('trip_agg_data_2019'::REGCLASS,'trip_agg_data_20190501',2019050100,2019060100);

select attach_range_partition('trip_agg_data_2019'::REGCLASS,'trip_agg_data_20190601',2019060100,2019070100);

select attach_range_partition('trip_agg_data_2019'::REGCLASS,'trip_agg_data_20190701',2019070100,2019080100);

select attach_range_partition('trip_agg_data_2019'::REGCLASS,'trip_agg_data_20190801',2019080100,2019090100);

select attach_range_partition('trip_agg_data_2019'::REGCLASS,'trip_agg_data_20190901',2019090100,2019100100);

select attach_range_partition('trip_agg_data_2019'::REGCLASS,'trip_agg_data_20191001',2019100100,2019110100);

select attach_range_partition('trip_agg_data_2019'::REGCLASS,'trip_agg_data_20191101',2019110100,2019120100);

select attach_range_partition('trip_agg_data_2019'::REGCLASS,'trip_agg_data_20191201',2019120100,2020010100);

-- 6, disable parent for trip_agg_data_2019

select set_enable_parent('trip_agg_data_2019'::regclass,false);

alter table trip_agg_data alter column time_key set not null;

select create_range_partitions('trip_agg_data'::regclass,'time_key',0::bigint,1::bigint,0,false) ;

select add_range_partition('trip_agg_data'::REGCLASS,0,2019010100,'trip_agg_data_lt_20190101');

select add_range_partition('trip_agg_data'::REGCLASS,2019010100,2019020100,'trip_agg_data_20190101');

select add_range_partition('trip_agg_data'::REGCLASS,2019020100,2019030100,'trip_agg_data_20190201');

select add_range_partition('trip_agg_data'::REGCLASS,2019030100,2019040100,'trip_agg_data_20190301');

select add_range_partition('trip_agg_data'::REGCLASS,2019040100,2019050100,'trip_agg_data_20190401');

select add_range_partition('trip_agg_data'::REGCLASS,2019050100,2019060100,'trip_agg_data_20190501');

select add_range_partition('trip_agg_data'::REGCLASS,2019060100,2019070100,'trip_agg_data_20190601');

select add_range_partition('trip_agg_data'::REGCLASS,2019070100,2019080100,'trip_agg_data_20190701');

select add_range_partition('trip_agg_data'::REGCLASS,2019080100,2019090100,'trip_agg_data_20190801');

select add_range_partition('trip_agg_data'::REGCLASS,2019090100,2019100100,'trip_agg_data_20190901');

select add_range_partition('trip_agg_data'::REGCLASS,2019100100,2019110100,'trip_agg_data_20191001');

select add_range_partition('trip_agg_data'::REGCLASS,2019110100,2019120100,'trip_agg_data_20191101');

select add_range_partition('trip_agg_data'::REGCLASS,2019120100,2020010100,'trip_agg_data_20191201');

select add_range_partition('trip_agg_data'::REGCLASS,2020010100,2020020100,'trip_agg_data_20200101');

select add_range_partition('trip_agg_data'::REGCLASS,2020020100,2020030100,'trip_agg_data_20200201');

select add_range_partition('trip_agg_data'::REGCLASS,2020030100,2020040100,'trip_agg_data_20200301');

select add_range_partition('trip_agg_data'::REGCLASS,2020040100,2020050100,'trip_agg_data_20200401');

select add_range_partition('trip_agg_data'::REGCLASS,2020050100,2020060100,'trip_agg_data_20200501');

select add_range_partition('trip_agg_data'::REGCLASS,2020060100,2020070100,'trip_agg_data_20200601');

select add_range_partition('trip_agg_data'::REGCLASS,2020070100,2020080100,'trip_agg_data_20200701');

select add_range_partition('trip_agg_data'::REGCLASS,2020080100,2020090100,'trip_agg_data_20200801');

select add_range_partition('trip_agg_data'::REGCLASS,2020090100,2020100100,'trip_agg_data_20200901');

select add_range_partition('trip_agg_data'::REGCLASS,2020100100,2020110100,'trip_agg_data_20201001');

select add_range_partition('trip_agg_data'::REGCLASS,2020110100,2020120100,'trip_agg_data_20201101');

select add_range_partition('trip_agg_data'::REGCLASS,2020120100,2021010100,'trip_agg_data_20201201');

select add_range_partition('trip_agg_data'::REGCLASS,2021010100,2021020100,'trip_agg_data_20210101');

select add_range_partition('trip_agg_data'::REGCLASS,2021020100,2021030100,'trip_agg_data_20210201');

select add_range_partition('trip_agg_data'::REGCLASS,2021030100,2021040100,'trip_agg_data_20210301');

select add_range_partition('trip_agg_data'::REGCLASS,2021040100,2021050100,'trip_agg_data_20210401');

select add_range_partition('trip_agg_data'::REGCLASS,2021050100,2021060100,'trip_agg_data_20210501');

select add_range_partition('trip_agg_data'::REGCLASS,2021060100,2021070100,'trip_agg_data_20210601');

select add_range_partition('trip_agg_data'::REGCLASS,2021070100,2021080100,'trip_agg_data_20210701');

select add_range_partition('trip_agg_data'::REGCLASS,2021080100,2021090100,'trip_agg_data_20210801');

select add_range_partition('trip_agg_data'::REGCLASS,2021090100,2021100100,'trip_agg_data_20210901');

select add_range_partition('trip_agg_data'::REGCLASS,2021100100,2021110100,'trip_agg_data_20211001');

select add_range_partition('trip_agg_data'::REGCLASS,2021110100,2021120100,'trip_agg_data_20211101');

select add_range_partition('trip_agg_data'::REGCLASS,2021120100,2022010100,'trip_agg_data_20211201');

select add_range_partition('trip_agg_data'::REGCLASS,2022010100,2022020100,'trip_agg_data_20220101');

select add_range_partition('trip_agg_data'::REGCLASS,2022020100,2022030100,'trip_agg_data_20220201');

select add_range_partition('trip_agg_data'::REGCLASS,2022030100,2022040100,'trip_agg_data_20220301');

select add_range_partition('trip_agg_data'::REGCLASS,2022040100,2022050100,'trip_agg_data_20220401');

select add_range_partition('trip_agg_data'::REGCLASS,2022050100,2022060100,'trip_agg_data_20220501');

select add_range_partition('trip_agg_data'::REGCLASS,2022060100,2022070100,'trip_agg_data_20220601');

select add_range_partition('trip_agg_data'::REGCLASS,2022070100,2022080100,'trip_agg_data_20220701');

select add_range_partition('trip_agg_data'::REGCLASS,2022080100,2022090100,'trip_agg_data_20220801');

select add_range_partition('trip_agg_data'::REGCLASS,2022090100,2022100100,'trip_agg_data_20220901');

select add_range_partition('trip_agg_data'::REGCLASS,2022100100,2022110100,'trip_agg_data_20221001');

select add_range_partition('trip_agg_data'::REGCLASS,2022110100,2022120100,'trip_agg_data_20221101');

select add_range_partition('trip_agg_data'::REGCLASS,2022120100,2023010100,'trip_agg_data_20221201');

select add_range_partition('trip_agg_data'::REGCLASS,2023010100,2023020100,'trip_agg_data_20230101');

select add_range_partition('trip_agg_data'::REGCLASS,2023020100,2023030100,'trip_agg_data_20230201');

select add_range_partition('trip_agg_data'::REGCLASS,2023030100,2023040100,'trip_agg_data_20230301');

select add_range_partition('trip_agg_data'::REGCLASS,2023040100,2023050100,'trip_agg_data_20230401');

select add_range_partition('trip_agg_data'::REGCLASS,2023050100,2023060100,'trip_agg_data_20230501');

select add_range_partition('trip_agg_data'::REGCLASS,2023060100,2023070100,'trip_agg_data_20230601');

select add_range_partition('trip_agg_data'::REGCLASS,2023070100,2023080100,'trip_agg_data_20230701');

select add_range_partition('trip_agg_data'::REGCLASS,2023080100,2023090100,'trip_agg_data_20230801');

select add_range_partition('trip_agg_data'::REGCLASS,2023090100,2023100100,'trip_agg_data_20230901');

select add_range_partition('trip_agg_data'::REGCLASS,2023100100,2023110100,'trip_agg_data_20231001');

select add_range_partition('trip_agg_data'::REGCLASS,2023110100,2023120100,'trip_agg_data_20231101');

select add_range_partition('trip_agg_data'::REGCLASS,2023120100,2024010100,'trip_agg_data_20231201');

select add_range_partition('trip_agg_data'::REGCLASS,2024010100,2024020100,'trip_agg_data_20240101');

select add_range_partition('trip_agg_data'::REGCLASS,2024020100,2024030100,'trip_agg_data_20240201');

select add_range_partition('trip_agg_data'::REGCLASS,2024030100,2024040100,'trip_agg_data_20240301');

select add_range_partition('trip_agg_data'::REGCLASS,2024040100,2024050100,'trip_agg_data_20240401');

select add_range_partition('trip_agg_data'::REGCLASS,2024050100,2024060100,'trip_agg_data_20240501');

select add_range_partition('trip_agg_data'::REGCLASS,2024060100,2024070100,'trip_agg_data_20240601');

select add_range_partition('trip_agg_data'::REGCLASS,2024070100,2024080100,'trip_agg_data_20240701');

select add_range_partition('trip_agg_data'::REGCLASS,2024080100,2024090100,'trip_agg_data_20240801');

select add_range_partition('trip_agg_data'::REGCLASS,2024090100,2024100100,'trip_agg_data_20240901');

select add_range_partition('trip_agg_data'::REGCLASS,2024100100,2024110100,'trip_agg_data_20241001');

select add_range_partition('trip_agg_data'::REGCLASS,2024110100,2024120100,'trip_agg_data_20241101');

select add_range_partition('trip_agg_data'::REGCLASS,2024120100,2025010100,'trip_agg_data_20241201');

select add_range_partition('trip_agg_data'::REGCLASS,2025010100,2025020100,'trip_agg_data_20250101');

select add_range_partition('trip_agg_data'::REGCLASS,2025020100,2025030100,'trip_agg_data_20250201');

select add_range_partition('trip_agg_data'::REGCLASS,2025030100,2025040100,'trip_agg_data_20250301');

select add_range_partition('trip_agg_data'::REGCLASS,2025040100,2025050100,'trip_agg_data_20250401');

select add_range_partition('trip_agg_data'::REGCLASS,2025050100,2025060100,'trip_agg_data_20250501');

select add_range_partition('trip_agg_data'::REGCLASS,2025060100,2025070100,'trip_agg_data_20250601');

select add_range_partition('trip_agg_data'::REGCLASS,2025070100,2025080100,'trip_agg_data_20250701');

select add_range_partition('trip_agg_data'::REGCLASS,2025080100,2025090100,'trip_agg_data_20250801');

select add_range_partition('trip_agg_data'::REGCLASS,2025090100,2025100100,'trip_agg_data_20250901');

select add_range_partition('trip_agg_data'::REGCLASS,2025100100,2025110100,'trip_agg_data_20251001');

select add_range_partition('trip_agg_data'::REGCLASS,2025110100,2025120100,'trip_agg_data_20251101');

select add_range_partition('trip_agg_data'::REGCLASS,2025120100,2026010100,'trip_agg_data_20251201');

select add_range_partition('trip_agg_data'::REGCLASS,2026010100,2026020100,'trip_agg_data_20260101');

select add_range_partition('trip_agg_data'::REGCLASS,2026020100,2026030100,'trip_agg_data_20260201');

select add_range_partition('trip_agg_data'::REGCLASS,2026030100,2026040100,'trip_agg_data_20260301');

select add_range_partition('trip_agg_data'::REGCLASS,2026040100,2026050100,'trip_agg_data_20260401');

select add_range_partition('trip_agg_data'::REGCLASS,2026050100,2026060100,'trip_agg_data_20260501');

select add_range_partition('trip_agg_data'::REGCLASS,2026060100,2026070100,'trip_agg_data_20260601');

select add_range_partition('trip_agg_data'::REGCLASS,2026070100,2026080100,'trip_agg_data_20260701');

select add_range_partition('trip_agg_data'::REGCLASS,2026080100,2026090100,'trip_agg_data_20260801');

select add_range_partition('trip_agg_data'::REGCLASS,2026090100,2026100100,'trip_agg_data_20260901');

select add_range_partition('trip_agg_data'::REGCLASS,2026100100,2026110100,'trip_agg_data_20261001');

select add_range_partition('trip_agg_data'::REGCLASS,2026110100,2026120100,'trip_agg_data_20261101');

select add_range_partition('trip_agg_data'::REGCLASS,2026120100,2027010100,'trip_agg_data_20261201');

select add_range_partition('trip_agg_data'::REGCLASS,2027010100,2027020100,'trip_agg_data_20270101');

select add_range_partition('trip_agg_data'::REGCLASS,2027020100,2027030100,'trip_agg_data_20270201');

select add_range_partition('trip_agg_data'::REGCLASS,2027030100,2027040100,'trip_agg_data_20270301');

select add_range_partition('trip_agg_data'::REGCLASS,2027040100,2027050100,'trip_agg_data_20270401');

select add_range_partition('trip_agg_data'::REGCLASS,2027050100,2027060100,'trip_agg_data_20270501');

select add_range_partition('trip_agg_data'::REGCLASS,2027060100,2027070100,'trip_agg_data_20270601');

select add_range_partition('trip_agg_data'::REGCLASS,2027070100,2027080100,'trip_agg_data_20270701');

select add_range_partition('trip_agg_data'::REGCLASS,2027080100,2027090100,'trip_agg_data_20270801');

select add_range_partition('trip_agg_data'::REGCLASS,2027090100,2027100100,'trip_agg_data_20270901');

select add_range_partition('trip_agg_data'::REGCLASS,2027100100,2027110100,'trip_agg_data_20271001');

select add_range_partition('trip_agg_data'::REGCLASS,2027110100,2027120100,'trip_agg_data_20271101');

select add_range_partition('trip_agg_data'::REGCLASS,2027120100,2028010100,'trip_agg_data_20271201');

select add_range_partition('trip_agg_data'::REGCLASS,2028010100,2028020100,'trip_agg_data_20280101');

select add_range_partition('trip_agg_data'::REGCLASS,2028020100,2028030100,'trip_agg_data_20280201');

select add_range_partition('trip_agg_data'::REGCLASS,2028030100,2028040100,'trip_agg_data_20280301');

select add_range_partition('trip_agg_data'::REGCLASS,2028040100,2028050100,'trip_agg_data_20280401');

select add_range_partition('trip_agg_data'::REGCLASS,2028050100,2028060100,'trip_agg_data_20280501');

select add_range_partition('trip_agg_data'::REGCLASS,2028060100,2028070100,'trip_agg_data_20280601');

select add_range_partition('trip_agg_data'::REGCLASS,2028070100,2028080100,'trip_agg_data_20280701');

select add_range_partition('trip_agg_data'::REGCLASS,2028080100,2028090100,'trip_agg_data_20280801');

select add_range_partition('trip_agg_data'::REGCLASS,2028090100,2028100100,'trip_agg_data_20280901');

select add_range_partition('trip_agg_data'::REGCLASS,2028100100,2028110100,'trip_agg_data_20281001');

select add_range_partition('trip_agg_data'::REGCLASS,2028110100,2028120100,'trip_agg_data_20281101');

select add_range_partition('trip_agg_data'::REGCLASS,2028120100,2029010100,'trip_agg_data_20281201');

select add_range_partition('trip_agg_data'::REGCLASS,2029010100,2029020100,'trip_agg_data_20290101');

select add_range_partition('trip_agg_data'::REGCLASS,2029020100,2029030100,'trip_agg_data_20290201');

select add_range_partition('trip_agg_data'::REGCLASS,2029030100,2029040100,'trip_agg_data_20290301');

select add_range_partition('trip_agg_data'::REGCLASS,2029040100,2029050100,'trip_agg_data_20290401');

select add_range_partition('trip_agg_data'::REGCLASS,2029050100,2029060100,'trip_agg_data_20290501');

select add_range_partition('trip_agg_data'::REGCLASS,2029060100,2029070100,'trip_agg_data_20290601');

select add_range_partition('trip_agg_data'::REGCLASS,2029070100,2029080100,'trip_agg_data_20290701');

select add_range_partition('trip_agg_data'::REGCLASS,2029080100,2029090100,'trip_agg_data_20290801');

select add_range_partition('trip_agg_data'::REGCLASS,2029090100,2029100100,'trip_agg_data_20290901');

select add_range_partition('trip_agg_data'::REGCLASS,2029100100,2029110100,'trip_agg_data_20291001');

select add_range_partition('trip_agg_data'::REGCLASS,2029110100,2029120100,'trip_agg_data_20291101');

select add_range_partition('trip_agg_data'::REGCLASS,2029120100,2030010100,'trip_agg_data_20291201');

select add_range_partition('trip_agg_data'::REGCLASS,2030010100,2147483647,'trip_agg_data_gt_20300101');

select partition_table_concurrently ('trip_agg_data'::regclass,10000, 1.0);

select set_enable_parent('trip_agg_data'::regclass,false);

postgresql 怎么自动创建分区

在数据库日渐庞大的今天,为了方便对数据库数据的管理,比如按时间,按地区去统计一些数据时,基数过于庞大,多有不便。很多商业数据库都提供分区的概念,按不同的维度去存放数据,便于后期的管理,PostgreSQL也不例外。

PostgresSQL分区的意思是把逻辑上的一个大表分割成物理上的几块儿。分区不仅能带来访问速度的提升,关键的是,它能带来管理和维护上的方便。

分区的具体好处是:

某些类型的查询性能可以得到极大提升。

更新的性能也可以得到提升,因为表的每块的索引要比在整个数据集上的索引要小。如果索引不能全部放在内存里,那么在索引上的读和写都会产生更多的磁盘访问。

批量删除可以用简单的删除某个分区来实现。

可以将很少用的数据移动到便宜的、转速慢的存储介质上。

在PG里表分区是通过表继承来实现的,一般都是建立一个主表,里面是空,然后每个分区都去继承它。无论何时,都应保证主表里面是空的。

小表分区不实际,表在多大情况下才考虑分区呢?PostgresSQL官方给出的建议是:当表本身大小超过了机器物理内存的实际大小时(the size of the table should exceed the physical memory of the database server),可以考虑分区。

PG目前(9.2.2)仅支持范围分区和列表分区,尚未支持散列分区。

二、环境

系统环境:CentOS release 6.3 (Final)

PostgreSQL版本:PostgreSQL 9.2.2 on x86_64-unknown-linux-gnu, compiled by gcc (GCC) 4.4.6 20120305 (Red Hat 4.4.6-4), 64-bit

三、实现分区

3.1 创建主表

david=# create table tbl_partition (

david(# id integer,

david(# name varchar(20),

david(# gender boolean,

david(# join_date date,

david(# dept char(4));

CREATE TABLE

david=#

3.2 创建分区表

david=# create table tbl_partition_201211 (

check ( join_date = DATE '2012-11-01' AND join_date DATE '2012-12-01' )

) INHERITS (tbl_partition);

CREATE TABLE

david=# create table tbl_partition_201212 (

check ( join_date = DATE '2012-12-01' AND join_date DATE '2013-01-01' )

) INHERITS (tbl_partition);

CREATE TABLE

david=# create table tbl_partition_201301 (

check ( join_date = DATE '2013-01-01' AND join_date DATE '2013-02-01' )

) INHERITS (tbl_partition);

CREATE TABLE

david=# create table tbl_partition_201302 (

check ( join_date = DATE '2013-02-01' AND join_date DATE '2013-03-01' )

) INHERITS (tbl_partition);

CREATE TABLE

david=# create table tbl_partition_201303 (

check ( join_date = DATE '2013-03-01' AND join_date DATE '2013-04-01' )

) INHERITS (tbl_partition);

CREATE TABLE

david=# create table tbl_partition_201304 (

check ( join_date = DATE '2013-04-01' AND join_date DATE '2013-05-01' )

) INHERITS (tbl_partition);

CREATE TABLE

david=# create table tbl_partition_201305 (

check ( join_date = DATE '2013-05-01' AND join_date DATE '2013-06-01' )

) INHERITS (tbl_partition);

CREATE TABLE

david=#

3.3 分区键上建索引

david=# create index tbl_partition_201211_joindate on tbl_partition_201211 (join_date);

CREATE INDEX

david=# create index tbl_partition_201212_joindate on tbl_partition_201212 (join_date);

CREATE INDEX

david=# create index tbl_partition_201301_joindate on tbl_partition_201301 (join_date);

CREATE INDEX

david=# create index tbl_partition_201302_joindate on tbl_partition_201302 (join_date);

CREATE INDEX

david=# create index tbl_partition_201303_joindate on tbl_partition_201303 (join_date);

CREATE INDEX

david=# create index tbl_partition_201304_joindate on tbl_partition_201304 (join_date);

CREATE INDEX

david=# create index tbl_partition_201305_joindate on tbl_partition_201305 (join_date);

CREATE INDEX

david=#

对于开发人员来说,希望数据库是透明的,只管 insert into tbl_partition。对于数据插向哪个分区,则希望由DB决定。这点,ORACLE实现了,但是PG不行,需要前期人工处理下。

3.4 创建触发器函数

david=# CREATE OR REPLACE FUNCTION tbl_partition_insert_trigger()

RETURNS TRIGGER AS $$

BEGIN

IF ( NEW.join_date = DATE '2012-11-01' AND

NEW.join_date DATE '2012-12-01' ) THEN

INSERT INTO tbl_partition_201211 VALUES (NEW.*);

ELSIF ( NEW.join_date = DATE '2012-12-01' AND

NEW.join_date DATE '2013-01-01' ) THEN

INSERT INTO tbl_partition_201212 VALUES (NEW.*);

ELSIF ( NEW.join_date = DATE '2013-01-01' AND

NEW.join_date DATE '2013-02-01' ) THEN

INSERT INTO tbl_partition_201301 VALUES (NEW.*);

ELSIF ( NEW.join_date = DATE '2013-02-01' AND

NEW.join_date DATE '2013-03-01' ) THEN

INSERT INTO tbl_partition_201302 VALUES (NEW.*);

ELSIF ( NEW.join_date = DATE '2013-03-01' AND

NEW.join_date DATE '2013-04-01' ) THEN

INSERT INTO tbl_partition_201303 VALUES (NEW.*);

ELSIF ( NEW.join_date = DATE '2013-04-01' AND

NEW.join_date DATE '2013-05-01' ) THEN

INSERT INTO tbl_partition_201304 VALUES (NEW.*);

ELSIF ( NEW.join_date = DATE '2013-05-01' AND

NEW.join_date DATE '2013-06-01' ) THEN

INSERT INTO tbl_partition_201305 VALUES (NEW.*);

ELSE

RAISE EXCEPTION 'Date out of range. Fix the tbl_partition_insert_trigger() function!';

END IF;

RETURN NULL;

END;

$$

LANGUAGE plpgsql;

CREATE FUNCTION

david=#

说明:如果不想丢失数据,上面的ELSE 条件可以改成 INSERT INTO tbl_partition_error_join_date VALUES (NEW.*); 同时需要创建一张结构和tbl_partition 一样的表tbl_partition_error_join_date,这样,错误的join_date 数据就可以插入到这张表中而不是报错了。

附上出处链接:

PostGresql 分区表

插入数据的时候,会根据address_id算出它的hashcode值,然后落入到对应的分区表上。查询数据的时候,只要带入这个address_id作为查询条件,就会算出对应的hashcode的值,然后就可以直接去指定的分区表中查询检索数据,避免大表扫描,提升查询效率。

举个例子,有2000万的数据,做了hash分区,分出来20张表,在插入数据的时候把2000万的数据均匀分布到这20张表中,平均每张表的数据只有100万,那么查询某个数据的时候,就可以只查询其中的一个分区表,因为数据只有100万,远远比2000万小,所以速度更快

当前标题:postgresql表分区的简单介绍
分享网址:https://www.cdcxhl.com/article40/dscioho.html

成都网站建设公司_创新互联,为您提供关键词优化建站公司网站设计公司做网站网站收录网站导航

广告

声明:本网站发布的内容(图片、视频和文字)以用户投稿、用户转载内容为主,如果涉及侵权请尽快告知,我们将会在第一时间删除。文章观点不代表本网站立场,如需处理请联系客服。电话:028-86922220;邮箱:631063699@qq.com。内容未经允许不得转载,或转载时需注明来源: 创新互联

成都app开发公司