----- Original Message ----- > From: "Reindl Harald" <h.rei...@thelounge.net> > > but what about the dramatical reduced query-cache hits i see > in some peace of software switching to prepared statements? > > dbmail2 as example had around 300 sql-actions per second > dbmail3 using prepared statements currently around 1000 per second > > i can not imagine any better performance in a php-script since it > is stateless and you have to do the whole prepare in each request
True. I just read up a bit on MySQL's prepared statement handling; and while it *does* implement prepared statements, it still doesn't have a prepared statement *cache*. That is to say, prepared statements are connection-specific, and even if you prepare the same statement twice in the same connection it'll allocate the structures twice. Kind of... suboptimal :-) So yes, it is true that in an application that does not repeatedly execute the same query with different parameters, it is likely to actually incur a performance penalty. I really really REALLY wish MySQL would make work of a global prepared statement cache - then the application being stateless wouldn't matter. Percona's Peter Zaitsev has an interesting blog post about the whole thing here: http://www.mysqlperformanceblog.com/2006/08/02/mysql-prepared-statements/ -- Bier met grenadyn Is als mosterd by den wyn Sy die't drinkt, is eene kwezel Hy die't drinkt, is ras een ezel -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/mysql
