- Dathan Vance Pattishall - Sr. Programmer and mySQL DBA for FriendFinder Inc. - http://friendfinder.com/go/p40688
-->-----Original Message----- -->From: Hsiu-Hui Tseng [mailto:[EMAIL PROTECTED] -->Sent: Thursday, November 06, 2003 3:41 PM -->To: [EMAIL PROTECTED] -->Subject: select count(*) / select count(column) in innodb --> -->Hi, --> -->select count(*) is very slow in innodb (because it is a table scan). Is -->there any difference if I change it to select count(column). --> -->I did some test and some times select count(*) is really slow and some -->time -->select count(column) is slow. Could anyone help me? INNODB is slow because it’s a row level locking schema and the nature of transactions (e.g. what committed what's not etc). Heikki Tuuri will give a much more solid explanation then I could. At the conference he did give a prelude that this functionality taken for granted will improve in later versions of innodb. In the interim you can use Show table status like '<YOUR TABLE NAME%>'; But it's not very accurate with INNODB. --> -->If I need do a select(*) in innodb, is there any way to get away from the -->slowness? No, use MYISAM; --> -->In the sql, should we avoid doing select * or select count(*)? What is -->the -->reason? Well why transfer unneeded column values over your network? It makes a difference when these columns are big blobs / texts and the intention is not to do so. --> -->Thank you for your help! --> -->Hsiu-Hui --> --> -->-- -->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]
