Why is this MySQL select query slowing things down?

Question

I have this query:

"SELECT * FROM forum_posts WHERE post_deleted='0'"

I can see via New Relic that it's eating up 60% of my MySQL resources, and therefore slowing down my entire website.

I have no idea why such a simple query would slow anything down? My table is an InnoDB table, with index on "id".

Answer 1

• Create index on post_deleted
• Verify that post_deleted is of type boolean (tinyint, smallint, or even integer will outperform string)
• Don't compare against the string '0' but against the number 0.