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Date: Thu, 16 Oct 2014 10:59:01 -0700
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Subject: Re: [PHP-DEV] [PATCH - PR] Disable ATTR_EMULATE_PREPARES by default
 for PDO_Mysql
From: christopher.jones@oracle.com (christopher jones)



On 10/16/14, 8:47 AM, Rasmus Lerdorf wrote:
> On 10/16/2014 04:27 AM, Ferenc Kovacs wrote:
>> On Fri, Jun 15, 2012 at 3:01 AM, Anthony Ferrara <ircmaxell@gmail.com>
>> wrote:
>>
>>> Hello all,
>>>
>>> I raised this topic on list over a year ago (
>>> http://marc.info/?l=php-internals&m=130417646507744&w=2 ). It was
>>> determined that it wasn't time yet to disable prepared statement
>>> emulation for MySQL yet. However, Rasmus did mention that it was a
>>> possibility for 5.4 (
>>> http://marc.info/?l=php-internals&m=130418875017027&w=2 ). Since that
>>> ship has sailed, I submitted a pull request for trunk to change the
>>> default value of prepared statement emulation for MySQL.
>>>
>>> https://github.com/php/php-src/pull/108
>>>
>>> https://bugs.php.net/bug.php?id=54638
>>>
>>> Does this need to be an RFC (should I draft one)? Or can it just be
>>> pulled as-is?
>>>
>>> Thanks,
>>>
>>> Anthony
>>>
>>> --
>>> PHP Internals - PHP Runtime Development Mailing List
>>> To unsubscribe, visit: http://www.php.net/unsub.php
>>>
>>>
>> hi,
>>
>> do we want to change the default for this in PHP7?
>
> Honestly, I am not sure about this anymore. There is a significant
> performance benefit in doing client-side prepares. Last year I attempted
> to switch to server-side prepares on Etsy's production servers but it
> added 30-40ms of page latency because of the extra round trips. And yes,
> we were doing too many queries, but I fear if we change this default
> people won't understand where this slowdown is coming from.
>
> Of course, in some rare cases using server-side prepares might speed
> things up because of prepared statement caching in the server, but I
> have yet to see a case where that caching outweighs the extra tcp
> roundtrip overhead.
>
> I do agree that the default should probably be server-side since it is
> the least surprising. We just need to make it very very clear in the
> upgrade doc that this change will likely slow down peoples' apps and
> show them how to turn client-side prepares back on.
>
> -Rasmus
>

The MySQL team has been improving their server-side prepare code:
http://mysqlserverteam.com/re-factoring-some-internals-of-prepared-statements-in-5-7/

Chris

-- 
christopher.jones@oracle.com  http://twitter.com/ghrd