spamassassin-users December 2011 archive
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spamassassin-users: Re: Bayes and MySQL - does it actually work?

Re: Bayes and MySQL - does it actually work?

From: Henrik K <hege_at_nospam>
Date: Fri Dec 23 2011 - 14:20:59 GMT

On Fri, Dec 23, 2011 at 02:10:16PM +0000, wrote:
> On 23/12/11 11:29, Henrik K wrote:
> >> Performance with the database on physical disks simply wasn't
> >> keeping up with more than about double the average message rate (if
> >> that...), so I fell back to the "good enough" setup of putting the
> >> SA database on a RAMdisk,
> > I guess it still boils down to basics. No matter what the database server is
> > used for, same principles apply. If you have slooow disks, then things are
> > going to be slow.
> As I understand it, if the MySQL query cache is tuned appropriately,
> then most of the queries should not be touching disk anyway?

Enabling query cache will probably (marginally) slow things down. Bayes
queries are extremely random, so there's nothing to cache. Any write to the
table will invalidate caches anyway. And those writes happen every time a
token is read (atime is updated).