Hi Jim, It's probably the time taken to parse the query with so many IN () values than it is to actually look them up. You can get an idea of how long it takes to parse the query by comparing the time with 1 IN value vs. thousands without the IN values actually matching any rows (e.g. dummy values).
If you're using MySQL 3.23, I've noticed that the query parser seems much, much faster in 4.0. Matt ----- Original Message ----- From: "Knepley, Jim" Sent: Thursday, October 30, 2003 4:48 PM Subject: WHERE IN performance Is it anyone elses experience that queries with large IN stanzas in a WHERE clause don't scale very well? It seems like it's beyond a linear performance hit when I have a large number (thousands) of tokens in an IN clause, even when the matching field is indexed. Is this something that buffer tweaks can mitigate, or am I looking at a more fundamental issue with how IN in implemented? J -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED]
