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Cc: Andrew Chernow <ac@esilo.com>, Pavel Golub <pavel@gf.microolap.com>,
	Pavel Golub <pavel@microolap.com>,
	PostgreSQL Hackers <pgsql-hackers@postgresql.org>,
	pgsql-interfaces <pgsql-interfaces@postgresql.org>
Subject: Re: [HACKERS] PQdeleteTuple function in libpq
From: Alvaro Herrera <alvherre@commandprompt.com>
To: Merlin Moncure <mmoncure@gmail.com>
In-reply-to: <BANLkTinOKYn2rS+LvCvLfOjeKuvKQS4PiA@mail.gmail.com>
References: <147534417.20110601184310@gf.microolap.com>
	<4DE6A5B7.2070700@esilo.com>
	<707574086.20110602112826@gf.microolap.com>
	<4DE79A58.4010608@esilo.com> <1307026778-sup-415@alvh.no-ip.org>
	<BANLkTinOKYn2rS+LvCvLfOjeKuvKQS4PiA@mail.gmail.com>
Date: Thu, 02 Jun 2011 11:57:23 -0400
Message-Id: <1307030194-sup-4091@alvh.no-ip.org>
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Excerpts from Merlin Moncure's message of jue jun 02 11:33:28 -0400 2011:
> On Thu, Jun 2, 2011 at 10:02 AM, Alvaro Herrera
> <alvherre@commandprompt.com> wrote:

> > Seems pretty wasteful if you want to delete a single tuple from a large
> > result.  I think if you desired to compact the result to free some
> > memory after deleting a large fraction of the tuples in the result it
> > could be useful to do that, otherwise just live with the unused holes in
> > the storage area as suggested by Pavel.
> 
> That would work, but it would potentially invalidate external pointers
> to internal result data.  If you wanted to do this, it might be better
> to expose a compaction feature which can be invoked directly.

Wouldn't that also invalidate external pointers?

-- 
Álvaro Herrera <alvherre@commandprompt.com>
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