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From:Johan De Meersman Date:May 14 2012 4:17pm
Subject:Re: MySQL Community Server 5.1.63 has been released
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----- 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/



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Thread
MySQL Community Server 5.1.63 has been releasedSunanda Menon7 May
  • Re: MySQL Community Server 5.1.63 has been releasedBaron Schwartz7 May
    • Re: MySQL Community Server 5.1.63 has been releasedJohan De Meersman8 May
      • Re: MySQL Community Server 5.1.63 has been releasedJohan De Meersman14 May
        • Re: MySQL Community Server 5.1.63 has been releasedGovinda14 May
          • Re: MySQL Community Server 5.1.63 has been releasedJohan De Meersman14 May
            • Re: MySQL Community Server 5.1.63 has been releasedReindl Harald14 May
              • Re: MySQL Community Server 5.1.63 has been releasedJohan De Meersman14 May
                • RE: MySQL Community Server 5.1.63 has been releasedRick James14 May
          • RE: MySQL Community Server 5.1.63 has been releasedRick James14 May