Bug #98449 | SELECT from I_S.INNODB_COLUMNS is slow in 8.0 | ||
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Submitted: | 31 Jan 2020 12:25 | Modified: | 2 Nov 2023 6:26 |
Reporter: | Sergei Glushchenko | Email Updates: | |
Status: | Closed | Impact on me: | |
Category: | MySQL Server: Data Dictionary | Severity: | S5 (Performance) |
Version: | 8.0.19 | OS: | Any |
Assigned to: | CPU Architecture: | Any |
[31 Jan 2020 12:25]
Sergei Glushchenko
[31 Jan 2020 13:11]
MySQL Verification Team
Hello Sergei, Thank you for the report and feedback. regards, Umesh
[3 Feb 2020 8:33]
Sergei Glushchenko
Hi Umesh, Thank you for looking into this issue. I disagree however with severity of this bug. This bug is not specific to Debug builds, you can compare release builds of recent 8.0 and 5.7. Things get much worse if you have thousands of tables with tenth columns each. Also, I want to point out that this is recent regression caused by the fix for https://bugs.mysql.com/bug.php?id=93033
[3 Feb 2020 8:59]
MySQL Verification Team
Thank you Sergei for the feedback. Changing severity to S5(Performance). regards, Umesh
[16 Mar 2020 15:02]
Daniel Price
Posted by developer: Fixed as of the upcoming 8.0.21 release, and here's the proposed changelog entry from the documentation team: A regression introduced in MySQL 8.0.18 affected INFORMATION_SCHEMA.INNODB_COLUMNS query performance. Schema and table data dictionary objects were fetched repeatedly to retrieve partition column information.