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From: Tom Lane <[email protected]>
To: Zubkovsky, Sergey <[email protected]>
Cc: [email protected]
Subject: Re: pg_total_relation_size() and CHECKPOINT
Date: Thu, 13 Mar 2008 16:20:30 -0400
Message-ID: <[email protected]> (raw)
In-Reply-To: <[email protected]>
References: <[email protected]>

"Zubkovsky, Sergey" <[email protected]> writes:
> I've detected that a result value of pg_total_relation_size() for an
> actively updated table might be significantly differ from a result that
> is returned after explicit CHECKPOINT command execution.

Uh, can you show a specific example of what you mean?

> I understand the reasons of such behavior: cache buffers must be flushed
> in order to be sure that pg_total_relation_size() result will be like we
> expect.

I wouldn't think so.  The space for a page is allocated immediately when
needed --- its *contents* might not be up to date, but that shouldn't
affect pg_total_relation_size.

			regards, tom lane

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