Hi! On Dec 04, Gurupartap Davis wrote: > I'm converting a table to innodb from myisam in mysql 4.0 and I was > wondering why it takes sooo long to do a SELECT COUNT(*)
MyISAM stores total number of rows in MYI file header. It's read into memory when table is opened. So for SELECT COUNT(*) FROM MyISAM_table NySQL need not acess data or even index - it can return an answer immidiately. InnoDB doesn't store total number of rows anywhere (afaik). Regards, Sergei -- MySQL Development Team __ ___ ___ ____ __ / |/ /_ __/ __/ __ \/ / Sergei Golubchik <[EMAIL PROTECTED]> / /|_/ / // /\ \/ /_/ / /__ MySQL AB, http://www.mysql.com/ /_/ /_/\_, /___/\___\_\___/ Osnabrueck, Germany <___/ --------------------------------------------------------------------- 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
