Postgresql排序与limit组合场景性能极限优化详解

1 构造测试数据

create table tbl(id int, num int, arr int[]);
create index idx_tbl_arr on tbl using gin (arr);
create or replace function gen_rand_arr() returns int[] as $$
select array(select (1000*random())::int from generate_series(1,64));
$$ language sql strict;

insert into tbl select generate_series(1,3000000),(10000*random())::int, gen_rand_arr();

insert into tbl select generate_series(1,500), (10000*random())::int, array[350,514,213,219,528,753,270,321,413,424,524,435,546,765,234,345,131,345,351];