Bug #40644 | main.group_concat_max_len_func random failures | ||
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Submitted: | 11 Nov 2008 16:45 | Modified: | 8 Dec 2008 16:05 |
Reporter: | Matthias Leich | Email Updates: | |
Status: | Closed | Impact on me: | |
Category: | Tests: Server | Severity: | S3 (Non-critical) |
Version: | 5.1 | OS: | Any |
Assigned to: | Matthias Leich | CPU Architecture: | Any |
Tags: | sporadic |
[11 Nov 2008 16:45]
Matthias Leich
[13 Nov 2008 18:37]
Matthias Leich
I assume this problem is caused by the MyISAM feature concurrent_insert + weak testing code and not by a server bug.
[14 Nov 2008 17:54]
Matthias Leich
Experiment: ----------- The MyISAM feature concurrent_insert = ON allows that the following effect can happen: session 1: INSERT INTO t1 session 2: <do not "see" the just inserted row> <some delay> session 2: <"see" the just inserted row> My experience is that the delay is small and increases with the load on the testing box. SET @@session.group_concat_max_len = 10; INSERT into t1(rollno, name) values(1, 'Record_1'); INSERT into t1(rollno, name) values(2, 'Record_2'); INSERT into t1(rollno, name) values(1, 'Record_3'); INSERT into t1(rollno, name) values(3, 'Record_4'); INSERT into t1(rollno, name) values(1, 'Record_5'); INSERT into t1(rollno, name) values(3, 'Record_6'); INSERT into t1(rollno, name) values(4, 'Record_7'); SELECT id, rollno, group_concat(name) FROM t1 GROUP BY rollno; (*) id rollno group_concat(name) (*) 1 1 Record_1,R (*) 2 2 Record_2 (*) 4 3 Record_4,R (*) 7 4 Record_7 (*) Warnings: (*) Warning 1260 2 line(s) were cut by GROUP_CONCAT() INSERT into t1(rollno, name) values(4, 'Record_8'); SELECT id, rollno, group_concat(name) FROM t1 GROUP BY rollno; (**) id rollno group_concat(name) (**) 1 1 Record_1,R (**) 2 2 Record_2 (**) 4 3 Record_4,R (**) 7 4 Record_7,R (**) Warnings: (**) Warning 1260 3 line(s) were cut by GROUP_CONCAT() (**) Is the result set expected by the current test. (*) Is the result set which we could get if the last row is not on disk. It equals the result set got during the failing run.
[14 Nov 2008 18:20]
Bugs System
A patch for this bug has been committed. After review, it may be pushed to the relevant source trees for release in the next version. You can access the patch from: http://lists.mysql.com/commits/58828 2709 Matthias Leich 2008-11-14 Fix for Bug#40644 main.group_concat_max_len_func random failures + minor improvements
[17 Nov 2008 0:55]
Patrick Crews
Ok to push. Tested patch on Mac OSX 10.5 and Windows XP 32 bit without incident.
[26 Nov 2008 16:05]
Matthias Leich
Pushed to 6.0-bugteam 5.1-bugteam
[8 Dec 2008 10:22]
Bugs System
Pushed into 5.1.31 (revid:matthias.leich@sun.com-20081114182016-kmna73w3gir2q4be) (version source revid:patrick.crews@sun.com-20081126215253-rub0b9ykdsgx9fvl) (pib:5)
[8 Dec 2008 11:33]
Bugs System
Pushed into 6.0.9-alpha (revid:matthias.leich@sun.com-20081114182016-kmna73w3gir2q4be) (version source revid:satya.bn@sun.com-20081126062555-dw4wp7jun7hoysdb) (pib:5)
[8 Dec 2008 16:05]
Paul DuBois
Test case changes. No changelog entry needed.
[19 Jan 2009 11:26]
Bugs System
Pushed into 5.1.31-ndb-6.2.17 (revid:tomas.ulin@sun.com-20090119095303-uwwvxiibtr38djii) (version source revid:tomas.ulin@sun.com-20090108105244-8opp3i85jw0uj5ib) (merge vers: 5.1.31-ndb-6.2.17) (pib:6)
[19 Jan 2009 13:04]
Bugs System
Pushed into 5.1.31-ndb-6.3.21 (revid:tomas.ulin@sun.com-20090119104956-guxz190n2kh31fxl) (version source revid:tomas.ulin@sun.com-20090119104956-guxz190n2kh31fxl) (merge vers: 5.1.31-ndb-6.3.21) (pib:6)
[19 Jan 2009 16:10]
Bugs System
Pushed into 5.1.31-ndb-6.4.1 (revid:tomas.ulin@sun.com-20090119144033-4aylstx5czzz88i5) (version source revid:tomas.ulin@sun.com-20090119144033-4aylstx5czzz88i5) (merge vers: 5.1.31-ndb-6.4.1) (pib:6)