Re: Memory Usage and libpq

From: Terry Lee Tucker <terry(at)esc1(dot)com>
To: Postgres-Interfaces <pgsql-interfaces(at)postgresql(dot)org>
Subject: Re: Memory Usage and libpq
Date: 2006-04-04 18:23:19
Message-ID: 200604041423.19119.terry@esc1.com
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On Tuesday 04 April 2006 03:14 pm, Keary Suska saith:
> I am investigating a memory usage issue and I noticed something with libpq.
> It appears that libpq doesn't actually free memory allocated to store
> results, even after PQclear() is called. In a debug program I can inspect
> the buffer so I know it exists. I haven't verified whether the buffer is
> resized with subsequent calls, but when dealing with large result sets it
> creates a significant memory overhead.
>
> Am I on to something here or do I need to keep looking? If so, is there any
> way that I can force libpq to free or in some way drastically reduce this
> biffer?
>
> Thanks,
>
> Keary Suska
> (719) 473-6431
> (719) 440-9952 (cell)
>

Keary,

I may be wrong about this, but just because you can access the memory after
the call to PQclear, doesn't mean that the memory wasn't freed; it just means
it hasn't been reused yet. The address still exists and freeing the memory
doesn't "clear" it out.

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