Bug #28273 | GROUP_CONCAT and ORDER BY: No warning when result gets truncated. | ||
---|---|---|---|
Submitted: | 7 May 2007 8:24 | Modified: | 7 Jun 2007 16:25 |
Reporter: | Martin Hansson | Email Updates: | |
Status: | Closed | Impact on me: | |
Category: | MySQL Server: Optimizer | Severity: | S3 (Non-critical) |
Version: | 5.0 | OS: | Any |
Assigned to: | Martin Hansson | CPU Architecture: | Any |
[7 May 2007 8:24]
Martin Hansson
[7 May 2007 11:36]
MySQL Verification Team
Thank you for the bug report. Verified as described.
[8 May 2007 12:29]
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/26289 ChangeSet@1.2479, 2007-05-08 14:29:03+03:00, mhansson@linux-st28.site +4 -0 bug#28273: GROUP_CONCAT and ORDER BY: No warning when result gets truncated. When using GROUP_CONCAT with order by, a tree is used for the sorting, instead of normal nested loops join. But the code that outputs the warning was before the call to traverse the tree. Hence, there's no warning if the output gets trimmed to GROUP_CONCAT_MAX_LEN in this case.
[8 May 2007 12:34]
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/26290 ChangeSet@1.2479, 2007-05-08 14:34:40+03:00, mhansson@linux-st28.site +3 -0 bug#28273: GROUP_CONCAT and ORDER BY: No warning when result gets truncated. When using GROUP_CONCAT with order by, a tree is used for the sorting, instead of normal nested loops join. But the code that outputs the warning was before the call to traverse the tree. Hence, there's no warning if the output gets trimmed to GROUP_CONCAT_MAX_LEN in this case.
[11 May 2007 16:06]
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/26501 ChangeSet@1.2479, 2007-05-11 16:05:20+03:00, mhansson@linux-st28.site +3 -0 bug#28273: GROUP_CONCAT and ORDER BY: No warning when result gets truncated. When using GROUP_CONCAT with ORDER BY, a tree is used for the sorting, as opposed to normal nested loops join used when there is no ORDER BY. The tree traversal that generates the result counts the lines that have been cut down. (as they get cut down to the field's max_size) But the check of that count was before the tree traversal, so no warning was generated if the output is truncated. Fixed by moving the check to after the tree traversal.
[11 May 2007 16:06]
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/26504 ChangeSet@1.2479, 2007-05-11 15:38:18+03:00, mhansson@linux-st28.site +3 -0 bug#28273: GROUP_CONCAT and ORDER BY: No warning when result gets truncated. When using GROUP_CONCAT with ORDER BY, a tree is used for the sorting, as opposed to normal nested loops join used when there is no ORDER BY. The tree traversal that generates the result counts the lines that have been cut down. (as they get cut down to the field's max_size) But the check of that count was before the tree traversal, so no warning was generated if the output is truncated. Fixed by moving the check to after the tree traversal.
[20 May 2007 17:11]
Bugs System
Pushed into 5.0.44
[20 May 2007 17:13]
Bugs System
Pushed into 5.1.19-beta
[7 Jun 2007 16:25]
Jon Stephens
Thank you for your bug report. This issue has been committed to our source repository of that product and will be incorporated into the next release. If necessary, you can access the source repository and build the latest available version, including the bug fix. More information about accessing the source trees is available at http://dev.mysql.com/doc/en/installing-source.html Documented bugfix in 5.0.44 and 5.1.20 changelogs.
[6 Jun 2008 5:57]
dhiraj jakkali
how to increase group_concat max length