[wp-trac] [WordPress Trac] #14711: Indexes for comment_author_email and user_id

[WordPress Trac]

#14711: Indexes for comment_author_email and user_id
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 Reporter:  tellyworth    |       Owner:     
     Type:  defect (bug)  |      Status:  new
 Priority:  normal        |   Milestone:  3.1
Component:  Comments      |     Version:  3.0
 Severity:  normal        |    Keywords:     
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Comment(by tellyworth):

 Replying to [comment:3 mrmist]:
 > One thing to beware of with that would be the low cardinatlity on
 user_id on sites with few / a single author.  You could end up imposing
 drag on a query that pulls a lot of columns based on that.

 There are already indexes on several columns that are or could be low
 cardinality (comment_approved, comment_parent, comment_post_ID). Will
 adding user_id make a significant difference?

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Ticket URL: <http://core.trac.wordpress.org/ticket/14711#comment:4>
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