Hi, You're doing a join on 'BoardID' on the tables MSGS and MBOARD. Is the BoardID field indexed on the MSGS table too? If not then that may be your problem.
Cheers, Andrew On 15/7/05 23:31, "Jon Drukman" <[EMAIL PROTECTED]> wrote: > i'm trying to run this query: > > SELECT COUNT(1) FROM MSGS m, MBOARD b WHERE b.BaseType = 0 AND m.BoardID > = b.BoardID; > > MSGS has 9.5 million rows, and is indexed on BoardID > MBOARD has 69K rows and is indexed on BaseType > > EXPLAIN shows: > > mysql> explain SELECT COUNT(1) FROM MSGS m, MBOARD b WHERE b.BaseType = > 0 AND m.BoardID = b.BoardID; > +-------+------+------------------+------------+---------+-----------+-------+ > -------------+ > | table | type | possible_keys | key | key_len | ref | > rows | Extra | > +-------+------+------------------+------------+---------+-----------+-------+ > -------------+ > | b | ref | PRIMARY,BaseType | BaseType | 1 | const | > 48614 | | > | m | ref | BoardIndex | BoardIndex | 4 | b.BoardID | > 277 | Using index | > +-------+------+------------------+------------+---------+-----------+-------+ > -------------+ > > the query takes several minutes to run. shouldn't this be a simple case > of doing some math on index values? > > -jsd- > -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED]
