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From Michael Dick <michael.d.d...@gmail.com>
Subject Re: Code organization
Date Mon, 08 Jun 2009 18:04:15 GMT
On Mon, Jun 8, 2009 at 9:36 AM, Daryl Stultz <daryl@6degrees.com> wrote:

> On Fri, Jun 5, 2009 at 5:47 PM, Michael Dick <michael.d.dick@gmail.com
> >wrote:
>
> > I think the query isn't compiled until the first time you use it and then
> > it's cached by its string form. Might have to look at that code again to
> > verify though.
>
> ...
>
> > I don't think there's a significant performance difference between the
> two
> > (if the annotation worked). The annotations might be more expressive
> > though..
>
>
> I'm a bit confused. Are named queries a feature that exists solely for the
> purpose of reuse or is there a performance advantage?
>

There's no performance advantage to @NamedQueries.  NamedQueries will
perform identical to a static JPQL string - first time it's used we'll
compile and cache the generated SQL, optionally cache the results, etc. The
documentation on the query SQL cache [1] might be of interest though.

[1]
http://openjpa.apache.org/builds/latest/docs/manual/manual.html#ref_guide_cache_querysql

NamedQueries are more readable than a static JPQL string but you shouldn't
choose them to improve performance.

Regards,

-mike




>
> --
> Daryl Stultz
> _____________________________________
> 6 Degrees Software and Consulting, Inc.
> http://www.6degrees.com
> mailto:daryl@6degrees.com
>

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