Im trying to speed up a query. select project_id from timesheet ts where ts.del is null and signoff = 'A'
The output of explain is detailed below. +----+-------------+-------+------+-------------------------+------+-------- | id | select_type | table | type | possible_keys | key | key_len +----+-------------+-------+------+-------------------------+------+-------- | 1 | SIMPLE | ts | ALL | signoff,del,del_signoff | NULL | NULL +----+-------------+-------+------+-------------------------+------+-------- | ref | rows | Extra | +----+-------------+-------+------+-------------------------+------+-------- | NULL | 3907 | Using where | +----+-------------+-------+------+-------------------------+------+-------- An index exists on all three columns referred to, in addition to a combination of del and signoff. The indexes are listed as possible keys, but none used by the query; key = null. Can anyone suggest why? How can I optimise this? Thanks Terry -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED]
