Bug #8371 Incorrect results with MEMORY engine, hash indexed column
Submitted: 8 Feb 2005 15:58 Modified: 26 Feb 2005 19:02
Reporter: Dean Ellis Email Updates:
Status: Closed Impact on me:
None 
Category:MySQL Server Severity:S1 (Critical)
Version:4.1.10 OS:
Assigned to: Sergey Petrunya CPU Architecture:Any

[8 Feb 2005 15:58] Dean Ellis 
Description:
MEMORY engine produces incorrect result set searching against a hash indexed column (results are correct with btree index).  Per EXPLAIN, join type is always reported as const.

How to repeat:
CREATE TEMPORARY TABLE t1 ( a INT, INDEX (a) ) ENGINE=MEMORY;
INSERT INTO t1 VALUES (1),(2),(3),(4),(5);
SELECT a FROM t1 WHERE a = 1;
SELECT a FROM t1 WHERE a IN (1,3);
EXPLAIN SELECT a FROM t1 WHERE a IN (1,3);

Suggested fix:
n/a
[8 Feb 2005 21:23] Sergey Petrunya 
Fixed in 4.1.10
[26 Feb 2005 19:02] Paul DuBois 
Noted in 4.1.10 changelog.