----- Original Message -----
> From: "Reindl Harald" <h.reindl@stripped>
>
> 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
