From: Date: July 3 2008 9:23pm Subject: Re: mutex contention for the query cache List-Archive: http://lists.mysql.com/internals/35787 Message-Id: <729475c80807031223y39fcbb84l5244bd1b91dc67c0@mail.gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit On Thu, Jul 3, 2008 at 11:03 PM, Brian Aker wrote: >> We get numerous reports that the query cache actually slows things >> down on 8 core (and more) systems. > > Delete it. Seriously. It is an idea that has come and gone... could be > better done inside of an engine on query fragments. Could you elaborate why it would be better to have it there? Query fragments are of the same size, or bigger than the query results (unless one computes cartesian product joins which is rare). I suppose a storage engine could do a better job at detecting cases when some INSERT/UPDATE/DELETE operation didn't affect the cached fragments, but that seems to be a problem that is not related to poor qcache concurrency. Or they are somehow related? BR Sergey -- Sergey Petrunia, Lead Software Engineer MySQL AB, www.mysql.com Office: N/A Blog: http://s.petrunia.net/blog