Re: Change Request: Make PDO default to not emulate prepared statements for MySQL

On Sat, Apr 30, 2011 at 5:39 PM, Rasmus Lerdorf <rasmus@lerdorf.com> wrote: > On 04/30/2011 08:13 AM, Anthony Ferrara wrote: > >> I have already reported this issue on the bug tracker: >> http://bugs.php.net/bug.php?id=54638 >> >> But I figured it would be good to start a discussion on it here. To >> me, I consider this a pretty significant issue since it's not possible >> to do true prepared statements while using PDO. All the code to do so >> is there (and it does work). But it's just the single flag that >> defaults emulation to be on that's holding things up. >> >> Since it will fallback to using emulation mode if the library or >> server can't support prepared statements, I don't personally see any >> issue with changing the default in a point release. >> > > Do you realize why we did this in the first place? The common versions of > MySQL in use out there are not very clever when it comes to the native > prepared statement handling. First, there is no prepared statement cache, so > there is no benefit to doing them natively, but worse, when you use a native > prepared statement you completely miss the query result cache. As a result > emulated prepared statements are either the same speed or faster than the > native ones. Changing this default would result in a performance hit for > most people. It should be better documented, but that is the only problem I > see here. > > I disable query_cache on my machines, because it can cause performance and stability issues. http://www.mysqlperformanceblog.com/2011/04/10/should-we-give-a-mysqlquery-cache-a-second-chance/ Tyrael