I have one query, that basically reads from one table of 13 million rows, groups it by two fields, and inserts into a rollup table. The result set ends up being about 31,000 rows. This runs in about 2 minutes which is acceptable. However, I add an additional group by field, which will probably result in a million results and mysql goes to a crawl. It doesn't even max out one cpu as the former query does. Instead vmstat reports a process blocked and in wait, while mysql goes down to hardly any cpu. The box lags a tad bit like it's I/O related, but the I/O isn't abnormal. As soon as I use mysqladmin to kill the query everything is back to normal. I'll note the load goes above 3.0 when this is running but none of it's in CPU ...
I realize this is very vague, bu I'm just shooting in the dark here wondering if someone has seen similar oddities, and it might be resolvable by tuning some of the parameters. 3.23.49, precompiled from mysql.com 2.4.9-21smp Linux key_buffer=16M table_cache=128 sort_buffer=8M record_buffer=2M tmp_table_size=16M I've tried increasing these but didn't help. --------------------------------------------------------------------- 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
