Re: Memory leaks using refcursors

From: "Guillaume Smet" <guillaume(dot)smet(at)gmail(dot)com>
To: "Tom Lane" <tgl(at)sss(dot)pgh(dot)pa(dot)us>
Cc: "PostgreSQL JDBC" <pgsql-jdbc(at)postgresql(dot)org>, thierry(dot)buffet(at)fr(dot)nurun(dot)com
Subject: Re: Memory leaks using refcursors
Date: 2007-01-17 23:27:53
Message-ID: 1d4e0c10701171527u744fd81eh6de7908599349af3@mail.gmail.com
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Hi Tom,

On 1/17/07, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
> While I agree that the driver probably should do that, I'm not sure why
> you are having a problem. A cursor doesn't normally accumulate its
> result set in memory on the backend side, so I wouldn't have expected
> all that big a memory leak. What queries are you executing?

I don't know exactly how much queries are executed during this
transaction but it's a lot of queries and they are _all_ executed
through stored proc returning cursors.

The self contained test case is available here:
http://people.openwide.fr/~gsmet/postgresql/refcursor_problem/ and
especially the stored proc is in the readme file along with all the
instructions to run the test case.

I just run a test case with 10k iterations and the backend which
executes the queries uses 236 MB of memory before the commit.

--
Guillaume

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