Bug #101886 | select count(*) very slow on windows mysql server | ||
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Submitted: | 7 Dec 2020 6:50 | Modified: | 9 Dec 2020 6:21 |
Reporter: | jack jack | Email Updates: | |
Status: | Not a Bug | Impact on me: | |
Category: | MySQL Server | Severity: | S3 (Non-critical) |
Version: | 8.0.22 | OS: | Windows (win10 professional 2004) |
Assigned to: | CPU Architecture: | x86 (ryzen 4800u ,intel 8600k) | |
Tags: | select count, slow |
[7 Dec 2020 6:50]
jack jack
[8 Dec 2020 13:11]
MySQL Verification Team
Hi Mr. Jack, Thank you for your bug report. However, this is not a bug. A difference in the speed that you see between Windows and Linux with our 8.0.22 release are not due to our code. Simply, LInux has much faster filesystem caching. To check this , you can try to create all your tablespaces with direct, no cache access. This is available on most filesystems that are available on Linux. This is described in our Reference Manual. Not a bug.
[8 Dec 2020 13:53]
jack jack
but why the 8.0.11 version is faster? same pc, i only upgrade to 8.0.22 from 8.0.11 , before upgrade, it's 1s. after upgrade, it's 13s, so what change in 8.0.22 for windows
[8 Dec 2020 14:03]
MySQL Verification Team
Hi, There are no changes interim ...... could be due to the state of the filesystem cache.
[8 Dec 2020 15:42]
jack jack
..ok i will reinstall older version and test
[9 Dec 2020 6:21]
jack jack
i test old version, from 8.0.11 to 8.0.22, the count slow in 8.0.17 version, so i search result on https://dev.mysql.com/doc/relnotes/mysql/8.0/en/news-8-0-17.html#mysqld-8-0-17-bug. i fount Bug #29939617, but i dont know what it's change. so i search commit in github, https://github.com/mysql/mysql-server/search?q=&type=commits, but only the bug29939617 number cannot search anything ...