On Thu, Oct 17, 2002 at 08:50:43PM +0200, Corin Langosch wrote: > the table has about 12.000 rows total but the query should return > a max of about 100. mysql should split the query into two queries > and merge the results. > may be this could be done by joining the same table two times > and query each table only for one of the OR expression. > i'll try but for future versions of mysql, this should > be internally done i think... ;) > > Thursday, October 17, 2002, 4:07:01 PM, you wrote: > CL>> are normal indexes. Unluckily a query like: > CL>> ------ > CL>> EXPLAIN SELECT * FROM `telegramme` WHERE to_id = 3157 or owner_id = 3157 > CL>> ------ > CL>> returns very bad results: > CL>> ------ > CL>> table type possible_keys key key_len ref rows Extra > CL>> telegramme ALL to_id,owner_id NULL NULL NULL 11488 where used > CL>> ------ > CL>> how could this be optimized or is this a bug of mysql, because the > CL>> indexes exist but are not used (even if specified with use index(..)) ?!
Sounds like you should either: ALTER TABLE telegramme ADD INDEX combined (to_id, owner_id); or SELECT * FROM telegramme WHERE to_id = 3157 UNION SELECT * FROM telegramme WHERE owner_id = 3157; HTH -- Shane Allen <[EMAIL PROTECTED]> --------------------------------------------------------------------- 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
