1
CREATE TABLE t1(id INT);
2
INSERT INTO t1 VALUES (1),(2),(3),(4);
3
INSERT INTO t1 SELECT a.id FROM t1 a,t1 b,t1 c,t1 d;
4
SET @orig_debug = @@debug;
5
SET SESSION debug="d,subselect_exec_fail";
6
SELECT SUM(EXISTS(SELECT RAND() FROM t1)) FROM t1;
7
SUM(EXISTS(SELECT RAND() FROM t1))
9
SELECT REVERSE(EXISTS(SELECT RAND() FROM t1));
10
REVERSE(EXISTS(SELECT RAND() FROM t1))
12
SET SESSION debug=@orig_debug;