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From "Brill Pappin" <br...@pappin.ca>
Subject RE: Slow JPA
Date Thu, 24 Apr 2008 00:54:34 GMT
We had the same problem, but right now your in a better position to help the
developers debug the issue.
It's clearly an expected usage that's not working quite right.

- Brill 

-----Original Message-----
From: Alexander MacLennan [mailto:alex.maclennan@gmail.com] 
Sent: Tuesday, April 22, 2008 11:51 PM
To: users@openjpa.apache.org
Subject: Re: Slow JPA

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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