Re: RE : Query Performance

[ed...@mgrinformatica.com.br]

To see what exactly being going to/from database server, enable P6Spy.
I'm using p6spy with sqlprofiler tool, and I get exactly information passing between OJB and
database server (not only sql commands, but including data sen't and returned).


Edson Richter

> Hello,
>
> I think I need to give you more explanation.
> In our production environnement, a website page takes 6 minutes to be
> displayed. And I think it is not enough quick ;-)
> In order to find the performance problem, we added some logs and found that
> the following code was the problem (and takes 6 minutes) :
>
> list = broker.getCollectionByQuery(requete);
> broker.commitTransaction();
>
> This query returns only 10 records (with simple data, no lob).
> I thought it was an Oracle performance problem so with the debug mode, I
> found the generated query. This query is not optimised, but when I tried it
> on the database, it only takes 4 secondes to be executed.
> I'm sure that the mapping is bad but i don't understand such difference
> between executing a query directly from a database and with OJB.
>
> So here are my questions :
>
> 1) Is the query displayed in the log server (with obj properties
> org.apache.ojb.broker.accesslayer.sql.SqlGeneratorDefaultImpl.LogLevel=DEBUG
> ) really the query executed on the database by OJB?
>
> 2) How really works OJB to retrieve data from a database?
>
>
> Thanks a lot.
>
> Yannick
>
> -----Message d'origine-----
> De : Yannick Goujon [mailto:yannick.goujon@unilog.fr]
> Envoyé : mardi 16 mars 2004 14:56
> À : ojb-user@db.apache.org
> Objet : Query Performance
>
> Hi,
>
>
>
> We use Oracle 8.1.7 and we have performance problem with a query generated
> by OJB.
>
> With OJB, it takes 6 minutes (maybe due to a bad mapping).
>
> We found the generated query by changing the LogLevel of the sql generator
> (org.apache.ojb.broker.accesslayer.sql.SqlGeneratorDefaultImpl.LogLevel=DEBU
> G)
>
> When we try this query directly under sqlplus, it only takes 4 secondes!
>
> Can someone explain me why is it so long with OJB? Is it due to a bad
> mapping or a bad configuration of OJB?
>
>
>
> Thanks
>
>
>
> Yannick
>
>
>
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