text: -- @testpoint: 创建基于多个字段的表达式索引
  
  --1.创建表插入数据
  create table t_tb(num1 int, num2 int);
  insert into t_tb values(generate_series(1,1000), generate_series(1000,2000));
  --2.创建函数
  create function func_multi(num1 int, num2 int) return int
  IMMUTABLE
  as
  begin
  return num1*num2;
  end;
  /
  --3.创建索引
  drop index if exists idx;
  create index idx on t_tb(func_multi(num1, num2));
  --4.使用索引
  SET ENABLE_SEQSCAN=off;
  explain select count(num1) from t_tb where func_multi(num1, num2)>10000;
  select count(num1) from t_tb where func_multi(num1, num2)>10000;
  
  --tearDown
  drop table if exists t_tb cascade;
  drop function func_multi;