Wrong result when using SQL_BUFFER_RESULT if min/max loose scan is chosen

Bug #992405 reported by Igor Babaev on 2012-05-01
6
This bug affects 1 person
Affects Status Importance Assigned to Milestone
MariaDB
Fix Released
Medium
Timour Katchaounov

Bug Description

The following sequence of commands brings us to a wrong result in MariaDB 5.2 :

CREATE TABLE t1 (a int, b varchar(1), KEY (b,a) );
INSERT INTO t1 VALUES (1,NULL),(0,'a');
SINSERT INTO t1 VALUES (2,'x'),(0,'y');
SELECT SQL_BUFFER_RESULT MIN(a), b FROM t1 WHERE t1.b = 'a' GROUP BY b;

MariaDB [test]> SELECT SQL_BUFFER_RESULT MIN(a), b FROM t1 WHERE t1.b = 'a' GROUP BY b;
+--------+------+
| MIN(a) | b |
+--------+------+
| NULL | NULL |
+--------+------+

The result is correct without the modifier SQL_BUFFER_RESULT:

MariaDB [test]> SELECT MIN(a), b FROM t1 WHERE t1.b = 'a' GROUP BY b;
+--------+------+
| MIN(a) | b |
+--------+------+
| 0 | a |
+--------+------+

(See also bug #12640437 for mysql-5.6)

Related branches

Changed in maria:
status: New → Confirmed
importance: Undecided → Medium
assignee: nobody → Timour Katchaounov (timour)
milestone: none → 5.2
Changed in maria:
status: Confirmed → In Progress
Changed in maria:
status: In Progress → Fix Committed
Changed in maria:
status: Fix Committed → Fix Released
To post a comment you must log in.
This report contains Public information  Edit
Everyone can see this information.

Other bug subscribers