Bug #120869 Optimizer chooses 26x slower join order due to fanout misestimation despite histograms
Submitted: 5 Jul 10:46 Modified: 6 Jul 5:39
Reporter: Zack Morgan Email Updates:
Status: Verified Impact on me:
None 
Category:MySQL Server: Optimizer Severity:S5 (Performance)
Version:9.7.1 OS:Ubuntu (22.04.4 LTS)
Assigned to: CPU Architecture:x86 (x86_64, Intel(R) Xeon(R) Gold 5220)

File: Maximum allowed size is 50MB.
Description:
Privacy:

If the data you need to attach is more than 50MB, you should create a compressed archive of the data, split it to 50MB chunks, and upload each of them as a separate attachment.

To split a large file:

[5 Jul 10:48] Zack Morgan
Self-contained SQL testcase for join-order fanout misestimation before and after histograms.

Attachment: mysql_join_order_fanout_testcase.zip (application/x-zip-compressed, text), 8.87 KiB.