PostgreSQL 基于 inherits 实现分表的示例代码

create table "public"."sales_order_full" (
  "id" int8 not null default nextval('sales_order_mixed_id_seq'::regclass),
  "version_number varchar",
  "order_id" varchar(298),
  "country_cd varchar(29)", 
  "product_no" varchar(35),
  "serial_no" varchar(273),
  "qty" int4,
  "fiscal_qtr",
  "order_dt" time，
  primary key ("order_id")
)

create table "public"."sales_order_full" (
  "id" bigserial, -- bigserial 会自动创建名为 sales_order_full_id_seq 自增索引
  "version_number varchar",
  "order_id" varchar(298),
  "country_cd varchar(29)", 
  "product_no" varchar(35),
  "serial_no" varchar(273),
  "qty" int4,
  "fiscal_qtr", 
  "geo"， --所属大区
  "order_dt" time，
  primary key ("order_id")
)

-- 创建子表,并设置 full 表的父子关系
create table if not exists "sales_order_full_cp" (check(geo = 'cp')) 
inherits (sales_order_full);

-- 设置主键信息
alter table "sales_order_full_cp" add constraint "sales_order_full_cp_pkey" 
primary key (order_id);

-- 设置对应索引
create index "sales_order_full_cp_mixed_idx" on "public"."sales_order_full_cp" 
using btree (
  "fiscal_qtr",
  "order_id",
  "country_cd"    
);
      

 insert into sales_order_full_cp
 (order_id,geo,country_cd,product_no,serial_no,qty,fiscal_qtr,order_dt,version_number)
 select 
 -- 注意 geo 字段取自 sales_geo_config 表
 a.order_id,b.geo,a.country_cd,a.product_no,a.serial_no,a.qty,a.fiscal_qtr,a.order_dt,version_number
 from 
 sales_order_full_cp_all_data_bak a 
 left join sales_geo_config b on a.country_cd = b.country 
 where b.geo = 'cp';

 insert into sales_order_full_unknown
 (order_id,geo,country_cd,product_no,serial_no,qty,fiscal_qtr,order_dt,versionnumber)
 select 
 -- 注意 geo 直接默认
 a.order_id,'unknown',a.country_cd,a.product_no,a.serial_no,a.qty,a.fiscal_qtr,a.order_dt,versionnumber
 from 
 sales_order_full_cp_all_data_bak a 
 left join sales_geo_config b on a.country_cd = b.country 
 where b.geo is null or b.geo not in ('hd','cy','sy','cp');

->  parallel index only scan using sales_order_full_unknown 
->  parallel seq scan on sales_order_full_cp 
->  parallel seq scan on sales_order_full_cy
->  parallel seq scan on sales_order_sy
->  parallel seq scan on sales_order_full_hd

select count(*) from sales_order_full;
result: 330000000  

select count(*) from sales_order_all_data_bak;
result: 330000000

-- 结果相等 直接删，释放数据库空间
drop table  sales_order_all_data_bak； 

select * from sales_order_full where geo = 'hd' and xx = 'xx'
或
select * from sales_order_full_hd where xx = 'xx'

 insert into sales_order_full_cp
 (order_id,geo,country_cd,product_no,serial_no,qty,fiscal_qtr,order_dt,version_numer)
 select 
 a.order_id,b.geo,a.country_cd,a.product_no,a.serial_no,a.qty,a.fiscal_qtr,a.order_dt,versionnumber
 from 
 order_inbound inbound
 left join sales_geo_config b on inbound.country_cd = b.country 
 where b.geo = 'cp' and inbound.version_number = '001';



update sales_order_full_cp set order_status = 'closed' where order_id = 'xx';