From: Tom Lane <tgl@sss.pgh.pa.us>
To: Peter Childs <peterachilds@gmail.com>
Cc: pgsql-performance@postgresql.org
Subject: Re: doubt with pg_dump and high concurrent used databases
Date: Sun, 25 Nov 2007 14:35:27 -0500
Message-ID: <20568.1196019327@sss.pgh.pa.us> (raw)
In-Reply-To: <a2de01dd0711251115l935fd31n8e7d1526fdb08097@mail.gmail.com>
References: <4749A6ED.2010005@laotraesquina.com.ar>
<9D744F5C-08B2-4C85-B06A-1A9FAD533AB6@myemma.com>
<a2de01dd0711251115l935fd31n8e7d1526fdb08097@mail.gmail.com>
"Peter Childs" <peterachilds@gmail.com> writes:
> On 25/11/2007, Erik Jones <erik@myemma.com> wrote:
>>> Does the pg_dump create this kind of "consistent backups"? Or do I
>>> need to do the backups using another program?
>>
>> Yes, that is exactly what pg_dump does.
>>
> Yes so long as you are using transactions correctly. Ie doing a begin before
> each invoice and a commit afterwards if your not bothering and using auto
> commit you *may* have problems.
I think you need to qualify that a bit more. What you're saying is that
if an application has consistency requirements that are momentarily
violated during multi-statement updates, and it fails to wrap such
updates into a single transaction, then pg_dump could capture one of the
intermediate states. That's true, but it's hardly pg_dump's fault.
If there were a system crash partway through such a sequence, the
consistency requirements would be violated afterwards, too.
regards, tom lane
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To: pgsql-performance@postgresql.org
Cc: tgl@sss.pgh.pa.us, peterachilds@gmail.com
Subject: Re: doubt with pg_dump and high concurrent used databases
In-Reply-To: <20568.1196019327@sss.pgh.pa.us>
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