> Possibly because datestamp and 20041105 have different datatypes. > There's an implicit data conversion required for the comparison, which > in some cases prevents use of an index. Try writing '20041105' rather > than 20041105 and see if that makes a difference.
Nope.. :-/ mysql> explain SELECT * FROM campaign_t WHERE datestamp < '20041105'\g +------------+------+---------------+------+---------+------+--------+------------+ | table | type | possible_keys | key | key_len | ref | rows | Extra | +------------+------+---------------+------+---------+------+--------+------------+ | campaign_t | ALL | datestamp | NULL | NULL | NULL | 438473 | where used | +------------+------+---------------+------+---------+------+--------+------------+ I think someone's onto something though regarding the 'optimize' command. The above selection is actually a DELETE, and it results in about a 3% deletion of the table per day. This has been running for months (if not years) with no optimization. Is it possible that this table is so fragmented? -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED]
