Bug #83319 | Performance regression when changing character set to utf8mb4 | ||
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Submitted: | 10 Oct 2016 12:44 | Modified: | 14 Nov 2016 18:09 |
Reporter: | Steinar Gunderson | Email Updates: | |
Status: | Closed | Impact on me: | |
Category: | MySQL Server: Charsets | Severity: | S3 (Non-critical) |
Version: | 8.0.1 | OS: | Any |
Assigned to: | CPU Architecture: | Any |
[10 Oct 2016 12:44]
Steinar Gunderson
[14 Nov 2016 18:09]
Paul DuBois
Posted by developer: Noted in 8.0.1 changelog. Performance of UCA 9.0.0-based collations (for example, utf8mb4_0900_ai_ci) was improved.
[29 Nov 2016 15:45]
Steinar Gunderson
Posted by developer: Didrik pointed out we should also document the change of the max_length_for_sort_data from 1024 to 4096.
[31 Mar 2017 13:27]
Paul DuBois
Posted by developer: This change was reverted due to other 8.0.1 work that changed Unicode 9.0.0 collations from PAD SPACE to NO PAD. Consequently, these collations treat space like any other character.
[3 Apr 2017 10:03]
Paul DuBois
Posted by developer: Not all of this bug fix was reverted, so this part of the changelog entry still applies: Performance of UCA 9.0.0-based collations (for example, utf8mb4_0900_ai_ci) was improved. These collations are now faster than any other UCA collations.
[5 Jul 2017 15:37]
Paul DuBois
Posted by developer: Addition to changelog entry: Additionally, the max_length_for_sort_data system variable default value was increased from 1024 to 4096.