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Re: Performance JPA

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On 11/11/2015 12:50 AM, Cecil Westerhof wrote:
> On Wednesday 11 Nov 2015 01:56 CET, Arne Vajhøj wrote:
>> On 11/10/2015 2:07 AM, Cecil Westerhof wrote:
>>> In principal database logging is going to be enabled, but I am
>>> waiting already a week for this.
>>
>> If you enable logging of the generated SQL then you can start moving
>> on instead of waiting for somebody else.
>
> The problem was that logging did not work. But I understood that they
> solved the problem with that. Until know I was told to look at the
> logging of the unit tests. I do not think that you can be sure that
> unit tests will give an accurate representation of live behaviour.

If the problem really is JPA generating bad SQL then I would say that
there is a pretty big chance that you will spot it already in the unit
tests.

You are not looking for 10% fine tuning of SQL - you are looking
for something big causing a x10 difference.

Even if it did not come up with something definite then the
exercise would give you a much better foundation for continuing
the troubleshooting.

>>> Yesterday I was told that the queries themselves do not take a lot
>>> of time.
>>
>> If that is true, which it may not be, then that points to not
>> being database.
>
> I found that even if they find it annoying I have to check and recheck
> what I am told. For example the what I was told about the timings was
> not correct. I was told 5 seconds with JDBC and 2 minutes with JPA.
> That turned out to be 1 second and 19 seconds. Less of a difference,
> but still way of.

That sort of problems is unfortunately very common.

>> Do you have any potential complications: * relations that pull in
>> many extra rows without enabling lazy loading * relations that
>> convert single object update into many row updates
>
> Not directly, no. Here is the strange part. There are some relations,
> but they are manually fetched. In JDBC and JPA in the same way. So on
> the one hand that should not be a problem. But on the other hand when
> those fetches are disabled the JPA application is a lot faster.

I think you should pick one of these cases. Look at the SQL in the JDBC
version. And look at the generated SQL in the JPA version.

>>> I think it is time for profiling. As long as we are not sure what
>>> the problem is, it is impossible to solve it. Until now I never had
>>> to profile in Java. We work with Eclipse Kepler and IBM WebSpere
>>> Application Server v8.0. What are good resources to learn to
>>> profile the code?
>>
>> I would start by getting that logging enabled.
>
> There was a problem with that, but I was yesterday notified that this
> problem was solved.
>
> Something else: I do not think it could be a problem, but better save
> as sorry. I read somewhere that using @EmbeddedId could result in a
> performance hit. Is that true? If so what could be the reason for
> this? Because there are quit a few entities that use @EmbeddedId.

In very pure ORM then you would have a single synthetic PK field.

But the other should work fine as well.

No harm done in taking a quick look at the generated SQL though
to verify that it turns out OK.

Arne

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Thread

Performance JPA Cecil Westerhof <Cecil@decebal.nl> - 2015-11-02 09:47 +0100
  Re: Performance JPA Silvio <silvio@internet.com> - 2015-11-02 14:23 +0100
    Re: Performance JPA Cecil Westerhof <Cecil@decebal.nl> - 2015-11-03 07:52 +0100
      Re: Performance JPA Martin Gregorie <martin@address-in-sig.invalid> - 2015-11-03 11:16 +0000
        Re: Performance JPA Cecil Westerhof <Cecil@decebal.nl> - 2015-11-03 19:11 +0100
          Re: Performance JPA Martin Gregorie <martin@address-in-sig.invalid> - 2015-11-03 19:15 +0000
            Re: Performance JPA Cecil Westerhof <Cecil@decebal.nl> - 2015-11-04 09:28 +0100
              Re: Performance JPA Cecil Westerhof <Cecil@decebal.nl> - 2015-11-10 08:07 +0100
                Re: Performance JPA Silvio <silvio@internet.com> - 2015-11-10 10:35 +0100
                Re: Performance JPA Cecil Westerhof <Cecil@decebal.nl> - 2015-11-11 06:20 +0100
                Re: Performance JPA Arne Vajhøj <arne@vajhoej.dk> - 2015-11-11 09:32 -0500
                Re: Performance JPA Arne Vajhøj <arne@vajhoej.dk> - 2015-11-10 19:56 -0500
                Re: Performance JPA Cecil Westerhof <Cecil@decebal.nl> - 2015-11-11 06:50 +0100
                Re: Performance JPA Martin Gregorie <martin@address-in-sig.invalid> - 2015-11-11 12:17 +0000
                Re: Performance JPA Arne Vajhøj <arne@vajhoej.dk> - 2015-11-11 09:30 -0500
                Re: Performance JPA Cecil Westerhof <Cecil@decebal.nl> - 2015-11-11 23:20 +0100
                Re: Performance JPA Cecil Westerhof <Cecil@decebal.nl> - 2015-11-11 23:11 +0100
                Re: Performance JPA Arne Vajhøj <arne@vajhoej.dk> - 2015-11-11 19:10 -0500
                Re: Performance JPA Cecil Westerhof <Cecil@decebal.nl> - 2015-11-12 07:27 +0100
                Re: Performance JPA Cecil Westerhof <Cecil@decebal.nl> - 2015-11-13 08:30 +0100
                Re: Performance JPA Silvio <silvio@internet.com> - 2015-11-13 10:45 +0100
                Re: Performance JPA Cecil Westerhof <Cecil@decebal.nl> - 2015-11-13 11:06 +0100
                Re: Performance JPA Silvio <silvio@internet.com> - 2015-11-13 13:36 +0100
                Re: Performance JPA Cecil Westerhof <Cecil@decebal.nl> - 2015-11-20 09:04 +0100
                Re: Performance JPA Arne Vajhøj <arne@vajhoej.dk> - 2015-11-13 21:46 -0500
                Re: Performance JPA Cecil Westerhof <Cecil@decebal.nl> - 2015-11-20 09:09 +0100
          Re: Performance JPA Arne Vajhøj <arne@vajhoej.dk> - 2015-11-03 20:35 -0500
            Re: Performance JPA Cecil Westerhof <Cecil@decebal.nl> - 2015-11-04 09:35 +0100
              Re: Performance JPA Arne Vajhøj <arne@vajhoej.dk> - 2015-11-07 22:09 -0500
      Re: Performance JPA Silvio <silvio@internet.com> - 2015-11-03 12:29 +0100
        Re: Performance JPA Cecil Westerhof <Cecil@decebal.nl> - 2015-11-03 19:23 +0100
        Re: Performance JPA Arne Vajhøj <arne@vajhoej.dk> - 2015-11-03 20:44 -0500
          Re: Performance JPA Cecil Westerhof <Cecil@decebal.nl> - 2015-11-04 09:48 +0100
          Re: Performance JPA Silvio <silvio@internet.com> - 2015-11-04 10:23 +0100
            Re: Performance JPA Cecil Westerhof <Cecil@decebal.nl> - 2015-11-04 11:27 +0100
              Re: Performance JPA Silvio <silvio@internet.com> - 2015-11-04 12:42 +0100
                Re: Performance JPA Arne Vajhøj <arne@vajhoej.dk> - 2015-11-07 22:18 -0500
                Re: Performance JPA Silvio <silvio@internet.com> - 2015-11-09 10:43 +0100
                Re: Performance JPA Cecil Westerhof <Cecil@decebal.nl> - 2015-11-20 09:13 +0100
            Re: Performance JPA Arne Vajhøj <arne@vajhoej.dk> - 2015-11-07 22:12 -0500
              Re: Performance JPA Silvio <silvio@internet.com> - 2015-11-09 10:22 +0100
                Re: Performance JPA Arne Vajhøj <arne@vajhoej.dk> - 2015-11-10 21:35 -0500
                Re: Performance JPA Silvio <silvio@internet.com> - 2015-11-11 11:29 +0100
      Re: Performance JPA Arne Vajhøj <arne@vajhoej.dk> - 2015-11-03 20:42 -0500
        Re: Performance JPA Cecil Westerhof <Cecil@decebal.nl> - 2015-11-04 11:19 +0100
          Re: Performance JPA Arne Vajhøj <arne@vajhoej.dk> - 2015-11-07 22:05 -0500
  Re: Performance JPA Arne Vajhøj <arne@vajhoej.dk> - 2015-11-02 20:08 -0500
    Re: Performance JPA Cecil Westerhof <Cecil@decebal.nl> - 2015-11-03 07:55 +0100
      Re: Performance JPA Arne Vajhøj <arne@vajhoej.dk> - 2015-11-03 20:45 -0500
  Re: Performance JPA Lew <lewbloch@gmail.com> - 2015-11-16 14:43 -0800

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