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From "Jeremy Bauer" <techhu...@gmail.com>
Subject Re: Slow JPA
Date Wed, 23 Apr 2008 21:43:24 GMT
Hi Alexander,

You could try taking advantage of SQL statement batching by enabling it on
the dictionary.  Batching is currently only enabled by default for DB2 and
Oracle providers but may work for postgres if the JDBC driver and
dictionary supports it.  Check out the docs on statement batching here:
http://openjpa.apache.org/builds/1.1.0-SNAPSHOT/docs/ref_guide_dbsetup_stmtbatch.html

If it works, you'll likely need to do a bit of tuning to get the best
performance for your application.

-Jeremy

On 4/22/08, Alexander MacLennan <alex.maclennan@gmail.com> wrote:
>
> Hi,
>
> Its taking quite a long time in my code to store 3d model graphs to a
> postgresql 8.3 backed db
>
> I am generating large data sets.. so I would expect it not to be
> super-quick
>
> The data is being loaded in a loop, for each 3d model.. generate features
> and store both the features and the model
>
> At the end of each loop iteration I persist the objects.. is there a
> smarter
> way of doing it so the commit speeds up?
>
> I have a Q9450, lots of memory and the db is sitting on a pair of
> (mirrored)
> 76GB WD Raptors ( there goes my scholarship money ).
>
> I'm using java6
>
> cheers
>
> Alex
>
>
> On Fri, Apr 4, 2008 at 11:18 PM, Patrick Linskey <plinskey@gmail.com>
> wrote:
>
> > Hi,
> >
> > Are you calling merge() or persist() a lot? There's a known
> > inefficiency in 1.1.0-SNAPSHOT (not 1.0) with merging right now.
> >
> > Also, what does the generated SQL look like in your examples?
> >
> > -Patrick
> >
> > On Fri, Apr 4, 2008 at 7:55 AM, Brill Pappin <brill@pappin.ca> wrote:
> > > We were using 1.0 in this project, but its showing up in another
> > >  project using 1.1.
> > >
> > >  I really *want* to use ojpa but I don't have time to mess around and
> > >  the problem is significant.
> > >  There seem to be other inefficiencies as well that don't seem to need
> > >  to be there.
> > >
> > >  Not sure what we're going to do about it though, all the ORM
> > >  frameworks are going through some sort of growing pain at the moment
> > >  and I can't say I'm happy with any of them.
> > >
> > >  - Brill Pappin
> > >
> > >
> > >
> > >  On Fri, Apr 4, 2008 at 10:44 AM, Patrick T <soberdrunk22@hotmail.com>
> > wrote:
> > >  >
> > >  >  My issue is even just fetching the entities. Despite of changing
> > >  >  relationships to LAZY fetch, I find that querying the DB takes a
> > really long
> > >  >  time. I have experienced the commit issue as well,but I've worked
> > around
> > >  >  that by being careful on what I cascade through different
> entities.
> > >  >
> > >  >
> > >  >
> > >  >  Brill Pappin wrote:
> > >  >  >
> > >  >  > As a rule you can expect *any* orm framework to be slower than
> > simple
> > >  >  > JDBC,
> > >  >  > there is simply more to do... What you gain from it is ease of
> > maintenance
> > >  >  > and implementation which will save you time later (often a lot
> of
> > time).
> > >  >  > As with anything, you need to weigh the benefits of any solution
> > over
> > >  >  > another but in my experience most applications don't require
> such
> > high
> > >  >  > throughput that anyone would notice a couple of milliseconds
> saved
> > here
> > >  >  > and
> > >  >  > there... Of course it'll depend on what your doing :)
> > >  >  >
> > >  >  > However...
> > >  >  >
> > >  >  > I've just been doing some work tonight, and am finding that
> > begin() ->
> > >  >  > commit() transactions take longer and longer (in my case I have
> a
> > very
> > >  >  > large
> > >  >  > update that is broken down into chunks). I haven't traced the
> > problem yet
> > >  >  > and it may be configuration related, however the time grows
> > exponentially.
> > >  >  > Does that sound like the same problem you are having?
> > >  >  >
> > >  >  > - Brill
> > >  >  >
> > >  >  > -----Original Message-----
> > >  >  > From: Patrick T [mailto:soberdrunk22@hotmail.com]
> > >  >  > Sent: Friday, March 28, 2008 3:55 PM
> > >  >  > To: users@openjpa.apache.org
> > >  >  > Subject: Slow JPA
> > >  >  >
> > >  >  >
> > >  >  > Hello Everyone,
> > >  >  >
> > >  >  > I'm just wondering if anyone else is finding JPA slower than
> > simple jdbc
> > >  >  > implementations. I have tried setting up some of the attributes
> to
> > Lazy
> > >  >  > fetch and I still find it to be extremely slow. This is causing
> my
> > web
> > >  >  > pages
> > >  >  > to load in the upwards of 10 seconds. I have tried running the
> > PCEnhancer
> > >  >  > and still takes a long time to fetch data. Does anyone have any
> > >  >  > suggestions
> > >  >  > to speed it up? Thanks.
> > >  >  >
> > >  >  > Patrick
> > >  >  > --
> > >  >  > View this message in context:
> > >  >  > http://www.nabble.com/Slow-JPA-tp16360845p16360845.html
> > >  >  > Sent from the OpenJPA Users mailing list archive at Nabble.com.
> > >  >  >
> > >  >  >
> > >  >  >
> > >  >
> > >  >  --
> > >  >  View this message in context:
> > http://www.nabble.com/Slow-JPA-tp16360845p16491755.html
> > >  >  Sent from the OpenJPA Users mailing list archive at Nabble.com.
> > >  >
> > >  >
> > >
> >
> >
> >
> > --
> > Patrick Linskey
> > 202 669 5907
> >
>

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