Bug #5311 | "const" row read breaks order by optimization | ||
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Submitted: | 31 Aug 2004 3:19 | Modified: | 8 Sep 2004 6:01 |
Reporter: | Peter Zaitsev (Basic Quality Contributor) | Email Updates: | |
Status: | Not a Bug | Impact on me: | |
Category: | MySQL Server | Severity: | S3 (Non-critical) |
Version: | 4.1.4 | OS: | Any (all) |
Assigned to: | Timour Katchaounov | CPU Architecture: | Any |
[31 Aug 2004 3:19]
Peter Zaitsev
[31 Aug 2004 4:10]
MySQL Verification Team
Thank you for the bug report I was able to repeat with latest Windows server.
[8 Sep 2004 6:01]
Timour Katchaounov
Thank you for taking the time to write to us, but this is not a bug. Please double-check the documentation available at http://www.mysql.com/documentation/ and the instructions on how to report a bug at http://bugs.mysql.com/how-to-report.php Additional info: Currently MySQL does not support such an optimization. More precisely, the optimizer does indeed detect constant tables based on schema information, however this information is not propagated to the later optimization phase where it is decided if ORDER BY can be computed without sorting by index access only, that is, the optimizer does not consider t2.j to be a constant, thus there is no constant prefix to search in index j. Such an optimization will be added as a new feature in an upcoming version of MySQL.