MySQL Bugs: #120793: Default heuristic pruning misses join-connected prefix in 3-table query, causing ~40x slower plan

Bug #120793	Default heuristic pruning misses join-connected prefix in 3-table query, causing ~40x slower plan
Submitted:	27 Jun 11:52	Modified:	8 Jul 9:30
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 (Intel(R) Xeon(R) Gold 5220 CPU @ 2.20GHz)
Tags:	heuristic-pruning, join-order, natural-join, Optimizer, optimizer-prune-level, performance

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:

On *nix platforms use the split command e.g. split -b 50MB <my_large_archive> <my_split_archive_prefix>
On windows use WinZip or a similar utility to split the large file

SQL scripts to reproduce a MySQL 9.7.1 join-order heuristic pruning performance issue.

Attachment: mysql971-3table-join-order-pruning-repro.zip (application/x-zip-compressed, text), 7.06 KiB.

mysql_bug120793_scaled_supplement_repro sql file and output file

Attachment: mysql_bug120793_scaled_supplement_repro.zip (application/x-zip-compressed, text), 4.91 KiB.