Groups > comp.lang.java.programmer > #33127

Re: Performance JPA

From	Arne Vajhøj <arne@vajhoej.dk>
Newsgroups	comp.lang.java.programmer
Subject	Re: Performance JPA
Date	2015-11-13 21:46 -0500
Organization	Aioe.org NNTP Server
Message-ID	<n2679d$gne$1@speranza.aioe.org> (permalink)
References	(8 earlier) <n1u3ne$hvk$1@speranza.aioe.org> <8737wc425d.fsf@Equus.decebal.nl> <n20ld4$3dd$1@speranza.aioe.org> <87pozf3f7b.fsf@Equus.decebal.nl> <87egfu2w6a.fsf@Equus.decebal.nl>

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On 11/13/2015 2:30 AM, Cecil Westerhof wrote:
> On Thursday 12 Nov 2015 07:27 CET, Cecil Westerhof wrote:
>> On Thursday 12 Nov 2015 01:10 CET, Arne Vajhøj wrote:
>>> The technique may work fine for a local database with a simple
>>> login protocol but with a remote database and complex protocol,
>>> then it could create a huge overhead.
>>>
>>> But we would need to see the rest of the persistence,xml to be sure
>>> (the standard part actually determines whether it is driver or
>>> data source).
>>>
>>> Try see:
>>>
>>> http://stackoverflow.com/questions/3526434/ibm-websphere-jpa-configuration-how-to-update-persistence-xml
>>>
>>> for an example of a persistence.xml that looks way
>>> more I would expect (no driver, data source, all managed).
>>
>> I have been trying some things, but until now without success. I
>> need to go to the office again and from there I do not have
>> newsgroup access, so some silence on my part again. I will
>> communicate my progress when I am back home.
>
> Problem solved. I removed openjpa.ConnectionDriverName and
> openjpa.jdbc.DBDictionary.

> The performance is now comparable with the performance of JDBC. So I
> proved the naysayers wrong.

:-)

> OneToMany relations are also going to be implemented, so maybe the JPA
> version will be even faster as the JDBC version. ;-)

Not necessarily faster but you may save even more code.

Note that when doing this then you will need to decide on eager vs
lazy loading.

> One question: I removed
>      <property name="openjpa.jdbc.DBDictionary" value="org.apache.openjpa.jdbc.sql.DB2Dictionary" />
>
> It works, but I was told that I could better put it back, because it
> was used to optimise complex queries. Is this true?

You are telling OpenJPA to use standard SQL and not any DB2 specific SQL
constructs.

It could mean a difference in some cases.

But in most cases no difference as what you usually do via ORM are
simple stuff that is covered fine by standard SQL.

I would add it back though. It does not hurt.

Arne

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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