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From "Patrick Linskey" <plins...@gmail.com>
Subject Re: Question: Application of QueryCompilationCache for find() and lazy relationships?
Date Tue, 16 Oct 2007 15:18:15 GMT
Hi,

Yes, SQL caching will be a big win. Sadly, as you point out, there is
no one clear spot to do the caching, and a number of things must be
incorporated into the key for the cache. That said, it's definitely
doable.

-Patrick

On 10/16/07, Kevin Sutter <kwsutter@gmail.com> wrote:
> Patrick,
> As I continued to look at this area, it really wasn't the lack of the Query
> Compilation Cache that was causing the performance concerns (as I believe
> you had already figured out).  But, rather, it's the constant re-generation
> of the dynamic SQL that is causing the performance concerns.  Even when
> dealing with named queries, the SQL is always generated from scratch when
> performing the execute().
>
> I've started to look at possibly caching the generated SQL or at least
> aspects of the SQL string, but so far, I have not found the "magic spots"
> for any necessary caches.  The generation of the SQL seems to be tightly
> bound with the processing of the query itself (setting parameters, setting
> hints, setting max results, etc).  Anyway, I am still digging into this
> during my spare time to see if I can help out with this performance
> concern...
>
> Thanks,
> Kevin
>
> On 10/11/07, Patrick Linskey <plinskey@gmail.com> wrote:
> >
> > The query compilation cache doesn't cache data that would be directly
> > useful for those calls. However, I'm all for optimizing those
> > pathways, and the query compilation cache could be a place to store
> > whatever intermediate caches we are able to assemble.
> >
> > -Patrick
> >
> > On 10/11/07, Kevin Sutter <kwsutter@gmail.com> wrote:
> > > Hi,
> > > For those of you that are more verse with the QueryCompilationCache, I'm
> > > wondering how difficult it would be to utilize this type of cache for
> > the
> > > em.find() operations as well as traversal of lazy relationships.  We're
> > > finding that these operations are more prevalent in customer's
> > applications
> > > than the use of createQuery() and createNamedQuery() operations and it's
> > > affecting our performance (especially as compared to our
> > competitors).  So,
> > > I am wondering whether anybody has put any thought in this space before
> > I do
> > > a deeper dive.  Any suggestions or thoughts?
> > >
> > > Thanks,
> > > Kevin
> > >
> >
> >
> > --
> > Patrick Linskey
> > 202 669 5907
> >
>


-- 
Patrick Linskey
202 669 5907

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