PostgreSQL分区表建立

pgsql 分区表：

--主表
create table test(id integer, name varchar(32));
create index idx_test_id on test using btree(id);

--分表
create table test_b (like test including constraints including defaults including indexes) inherits(test);
create table test_c (like test including constraints including defaults including indexes) inherits(test);


alter table test_b add constraint con_test_c check(id >=1001 and id <= 2000);
alter table test_c add constraint con_test_b check(id >=2001 and id <= 3000);

create table test_d( check(id >=3001 and id <= 4000))inherits (test);

--插数据
insert into test_b select generate_series(1001,2000),‘bbb‘;
insert into test_c select generate_series(2001,3000),‘ccc‘;
insert into test_d select generate_series(3001,4000),‘ddd‘;

--分析表，加入计划
analyze test_a;

analyze test_b;

analyze test_c;
analyze test_d;

--测试查询计划 constraint_exclusion
set  constraint_exclusion = off/partition;
show constraint_exclusion;

explain select * from test where id = 1;


--测试Insert
insert into test values (11,‘aaaaa‘);

select * from test where name = ‘aaaaa‘

select * from test_a;



insert into test values(1,‘a‘),(1111,‘v‘),(2222,‘vv‘);


select * from test_c;

--创建触发器函数
create function tb_partition_insert()
returns trigger  as
$$
begin
if (id >=1 and id <= 1000) then
    insert into test_a values(NEW.*);
elseif (id >=1001 and id <= 2000) then
    insert into test_b values(NEW.*);
  elseif (id >=2001 and id <= 3000) then
   insert into test_c values (new.*);
   else
    raise exception ‘Date out of range. Fix the tbl_partition_insert_trigger() function!‘;
 end if ;
return null;
 end
$$
language plpgsql;

--触发器
create trigger insert_test_parition
    before insert on test
    for each row execute procedure tb_partition_insert();


--测试Insert
insert into test values(1,‘a‘),(1111,‘v‘),(2222,‘vv‘);

select pg_size_pretty(pg_relation_size(‘test‘));

insert into test select generate_series(1,1000),‘aa‘;
select count(1) from test_a;


select pg_size_pretty(pg_relation_size(‘test‘));

select pg_table_size(‘test‘)