mariadb/mysql-test/main/stack.test

--echo # Checking stack usage

--echo #
--echo # basic tests
--echo #

select variable_value > 0 from information_schema.session_status where variable_name="stack_usage";


--echo #
--echo # Ensure stack usage is same for each iteration when using WITH recursive
--echo #

create table t1
WITH recursive Fibonacci(PrevN, N, Stack) AS
(
     SELECT 0, 1, 0
     UNION ALL
     SELECT N, PrevN + N, (select variable_value from information_schema.session_status where variable_name="stack_usage")
     FROM Fibonacci
     WHERE N < 100000
)
SELECT PrevN as N, Stack FROM Fibonacci;

select (select stack from t1 where n=2) = (select stack from t1 where N=75025) as c;
DROP table t1;

--echo #
--echo # Check stack with recursion
--echo #

set @@max_sp_recursion_depth=20;
delimiter $$;
create or replace procedure recursion(x int, max int, OUT res int)
begin
  select variable_value into res from information_schema.session_status where variable_name="stack_usage";
  if (x < max) then
    call recursion(x+1, max, res);
  end if;
end;
$$

delimiter ;$$

call recursion(0,2,@s1);
call recursion(0,3,@s2);
call recursion(0,4,@s3);

select @s1 > 0 && @s2 > 0 && @s3 > 0;
if (`select @s2-@s1 <> @s3 - @s2`)
{
  echo "Wrong result";
  select @s1 ,@s2, @s3, @s2-@s1, @s3-@s2;
}

drop procedure recursion;

--echo #
--echo # End of 10.5 tests
--echo #