Re: Memory Leak / Prepared Statement - Mailing list pgsql-jdbc

Barry,

I got OptimizeIt configured, and it looks like it is jdbc2/PreparedStatement
which is not being garbage collected.  All of my PreparedStatement s stay
visible in Optimize it and the number of instances never decreases.  What
other information can I provide to help determine if this is a memory leak or
another problem?  I am using Postgresql 7.1.2 and the driver that accompanied
it.

Thanks.

John

Barry Lind wrote:

> My guess is that this is unlikely to be the result of the ThreadLocal
> issues and also I doubt 1.4 will have any effect.  This sounds like a
> memory leak which could be in the driver or in your application code.  I
> also doubt that the use of LIKE is the problem as the JDBC code doesn't
> parse the SQL so it doesn't know if you are using LIKE or not.
>
> To fix this we would either need a reproducable test case that you could
> submit such that we could reproduce the problem and fix it, or you could
> use a java memory profiler to track down what objects are being
> allocated and not released.  I personally like OptimizeIt as it has
> helped me solve quite a few memory leak problems with java code.
>
> thanks,
> --Barry
>
> John Cook wrote:
>
> > Hi,
> >
> > I noticed several postings a month ago regarding a memory leak brought
> > about by the use of Thread.Local in jdbc2/PreparedStatement.java.  I
> > have what seems like a similar problem, but I am not sure.  I have
> > applied the patch, but I still have my problem (mine is not really
> > associated with DateFormat usage.)
> >
> > I am running Enhydra Application Server 3.1 on top of Postgres and I
> > have been running an application that tries to match text strings to
> > items in my database.  It has been running fine for months until
> > I recently made a modification that uses a lot of "LIKE" statements
> > (i.e. anywhere from 2-200 at a time.)  Performance is fine, but memory
> > starts getting eaten up and I eventually hits an OutOfMemoryError.  The
> > bigger the prepared statement (i.e. the more LIKEs) the more memory is
> > eaten and the faster I run out of memory.  Oddly enough, before I added
> > the LIKE statements, I was running fine and, although I used a lot of
> > prepared statements (the app server did), memory was not being eaten
> > like this.
> >
> > Has anyone had a similar experience and is it related to the
> > Thread.Local problem?  Does anyone know if this is addressed in the
> > 1.4.0 beta JDK or is it scheduled to be addressed in an upcoming
> > Postgresql release?
> >
> > Any help would be greatly appreciated.
> >
> > Thanks in advance.
> >
> > John Cook
> >
> >
> >
> >
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