Hi, I have a table with about 1.5M rows.
9 of the colums are varchar(9)'s. when I just select on one of them it goes fine, like: > explain select * from t1 where f2 = 'COM051000'; +-------+------+---------------+--------+---------+-------+------+------------+ | table | type | possible_keys | key | key_len | ref | rows | Extra | +-------+------+---------------+--------+---------+-------+------+------------+ | t1 | ref | f2_idx | f2_idx | 10 | const | 422 | where used | +-------+------+---------------+--------+---------+-------+------+------------+ 1 row in set (0.02 sec) (likewise for f1 = ...) But if I use f1 = ... or f2 = ... it doesn't use the index at all. > explain select * from t1 where f2 = 'COM051000' or f1 = 'COM051000'; +-------+------+---------------+------+---------+------+---------+------------+ | table | type | possible_keys | key | key_len | ref | rows | Extra | +-------+------+---------------+------+---------+------+---------+------------+ | t1 | ALL | f1_idx,f2_idx | NULL | NULL | NULL | 1194779 | where used | +-------+------+---------------+------+---------+------+---------+------------+ 1 row in set (0.01 sec) I tried running myisamchk -a on the table and now it shows the cardinality for each key correctly in "show keys from t1", but it didn't help on the queries. :-) I am sure this is something really obvious, but I've no clue (as you probably can gather from the above). What am I missing? What kind of thing can I do to make the above query go faster? Any hints would be appreciated. - ask -- ask bjoern hansen, http://ask.netcetera.dk/ !try; do(); more than a billion impressions per week, http://valueclick.com --------------------------------------------------------------------- Before posting, please check: http://www.mysql.com/manual.php (the manual) http://lists.mysql.com/ (the list archive) To request this thread, e-mail <[EMAIL PROTECTED]> To unsubscribe, e-mail <[EMAIL PROTECTED]> Trouble unsubscribing? Try: http://lists.mysql.com/php/unsubscribe.php
