Im have a problem / misunderstanding with the 4.1 release. Im having issues with indexes related to 'IN' vs '=' in subselects. assume the subselect returns 1 value
select SQL_NO_CACHE user_id from table_a where user_id in (select SQL_NO_CACHE user_id from table_b where ... blah) 9.5 seconds... select SQL_NO_CACHE user_id from table_a where user_id = (select SQL_NO_CACHE user_id from table_b where ... blah) 0.0 seconds explain select SQL_NO_CACHE user_id from table_a where user_id in (select SQL_NO_CACHE user_id from table_b where ... blah) ... not using index... explain select SQL_NO_CACHE user_id from table_a where user_id = (select SQL_NO_CACHE user_id from table_b where ... blah) .. using index on user_id and the subselect take 0.0 seconds to run as well.. Does just using the IN operator prohibit table_a from using the user_id index? Thanks Chris -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED]
