From: | Bruce Momjian <pgman(at)candle(dot)pha(dot)pa(dot)us> |
---|---|
To: | Doug McNaught <doug(at)mcnaught(dot)org> |
Cc: | Ben Clewett <B(dot)Clewett(at)roadrunner(dot)uk(dot)com>, Dave Page <dpage(at)vale-housing(dot)co(dot)uk>, pgsql-hackers(at)postgresql(dot)org |
Subject: | Re: For the ametures. (related to "Are we losing momentum?") |
Date: | 2003-04-17 16:40:42 |
Message-ID: | 200304171640.h3HGegL23646@candle.pha.pa.us |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-hackers |
Doug McNaught wrote:
> Ben Clewett <B(dot)Clewett(at)roadrunner(dot)uk(dot)com> writes:
>
>
> > > So does PostgreSQL (pg_dump/pg_dumpall).
> >
> > I have used this, and it's a great command.
> >
> > I could not work out from the documentation whether it takes a
> > snapshot at the start time, or archives data at the time it find's it.
> > The documentation (app-pg-dump.html). As the documentation does not
> > clarify this very important point, I desided it's not safe to use when
> > the system is in use.
>
> Ummm, quoting from the pg_dump manpage:
>
> pg_dump makes consistent backups even if the database is
> being used concurrently. pg_dump does not block other
> users accessing the database (readers or writers).
>
> What part of this isn't clear?
>
> It's safe. pg_dump does all its work inside a transaction, so MVCC
> rules automatically guarantee that it sees a consistent snapshot.
Too many people have missed that point --- it was too far down in the
manual page, after a long discussion about output formats. Now it is
right in the first paragraph, which should eliminate that question ---
it was almost becoming an FAQ.
--
Bruce Momjian | http://candle.pha.pa.us
pgman(at)candle(dot)pha(dot)pa(dot)us | (610) 359-1001
+ If your life is a hard drive, | 13 Roberts Road
+ Christ can be your backup. | Newtown Square, Pennsylvania 19073
From | Date | Subject | |
---|---|---|---|
Next Message | Jon Jensen | 2003-04-17 17:38:02 | Re: For the ametures. (related to "Are we losing momentum?") |
Previous Message | Doug McNaught | 2003-04-17 16:37:55 | Re: For the ametures. (related to "Are we losing momentum?") |