[wp-trac] [WordPress Trac] #26858: Comment duplicate check has a slow query
WordPress Trac
noreply at wordpress.org
Fri Jan 17 04:38:23 UTC 2014
#26858: Comment duplicate check has a slow query
--------------------------+------------------------------------
Reporter: pento | Owner:
Type: defect (bug) | Status: new
Priority: normal | Milestone: 3.9
Component: Database | Version: 2.0
Severity: normal | Keywords: has-patch dev-feedback
--------------------------+------------------------------------
When checking for duplicate comments, the query is pretty slow:
{{{
SELECT comment_ID FROM wp_comments WHERE comment_post_ID = '1' AND
comment_parent = '0' AND comment_approved != 'trash' AND ( comment_author
= 'foo' OR comment_author_email = 'foo at bar.com' ) AND comment_content =
'some content' LIMIT 1;
}}}
This will use the comment_post_ID index, which means it will scan all
comments on that post. For a post with thousands of comments, this starts
to get slow.
Instead, we should change `KEY comment_post_ID (comment_post_ID)` to `KEY
comment_post_ID (comment_post_ID,comment_content(255))`, to cover this
case.
Props [http://www.mysqlperformanceblog.com/2014/01/16/analyzing-wordpress-
mysql-queries-query-analytics/ MySQL Performance Blog] for finding this.
--
Ticket URL: <https://core.trac.wordpress.org/ticket/26858>
WordPress Trac <https://core.trac.wordpress.org/>
WordPress publishing platform
More information about the wp-trac
mailing list