[wp-trac] [WordPress Trac] #52559: When doing JOINs for meta queries the meta_key should be in the ON clause whenever possible.

[WordPress Trac]

#52559: When doing JOINs for meta queries the meta_key should be in the ON clause
whenever possible.
------------------------------+------------------------------
 Reporter:  herregroen        |       Owner:  (none)
     Type:  defect (bug)      |      Status:  new
 Priority:  normal            |   Milestone:  Awaiting Review
Component:  Query             |     Version:
 Severity:  normal            |  Resolution:
 Keywords:  needs-unit-tests  |     Focuses:  performance
------------------------------+------------------------------

Comment (by jeroendk):

 I encountered this issue as well for a post meta table with (only) 200k
 records, for now, I "fixed" it by adding an extra index to the wp_psotmeta
 table:

 {{{
 create index post_meta_combined_idx on wp_postmeta(post_id, meta_key)
 }}}

 Query times are now normal again.

-- 
Ticket URL: <https://core.trac.wordpress.org/ticket/52559#comment:2>
WordPress Trac <https://core.trac.wordpress.org/>
WordPress publishing platform