Thank you Dan, I will try that.
Mikhail Berman -----Original Message----- From: Dan Nelson [mailto:[EMAIL PROTECTED] Sent: Wednesday, May 03, 2006 5:29 PM To: Mikhail Berman Cc: Chris White; mysql@lists.mysql.com Subject: Re: Q2. Is there anything could be done to speed up this query In the last episode (May 03), Mikhail Berman said: > Thank you, Chris > > But the table is indexed on the field you are referring to and the > other one the query, which is evident from this: > > > KEY `prdadadx` (`price_data_date`), > > KEY `prdatidx` (`price_data_ticker`) These are two separate keys, though, and your query is doing a GROUP BY across both fields, so neither of those keys would be useful (mysql would have to do a random record lookup for each row to fetch the other field). Try an index on (price_data_ticker, price_data_date). Since your query only references those fields, mysql should be able to return your results just by scanning the index. -- Dan Nelson [EMAIL PROTECTED] -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED] -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED]
