Re: Trouble-free vacuum w/concurrent writes? (was"PostgreSQL capabilities")

Charles Tassell wrote:
>
> No, that's now what he said.  You can backup the database while it's still
> being used (the pg_dmp runs in a transaction) but you still can't vacuum a
> database while it's in use.  Vacuuming is more along the lines of a defrag,
> it updates the indexes and maintains stats.

Oops...I had blurred the two in my mind, as they are both a part of my
back-up process.  Thanks for pointing that out.  So, dumping concurrently
with reads/writes is fine, while vacuum with concurrent writes continues
to be problematic (though sounds like there will be some improvements on
the vacuum front in a coming release).

Regards,
Ed Loehr

> At 12:16 PM 5/31/00, Ed Loehr wrote:
> >Bruce Momjian wrote:
> > >
> > > > Alex Pilosov wrote:
> > > > >
> > > > > > http://networkdna.com/database/index.html mentions that PostgreSQL is
> > > > > > capable of "Online backup". What does that exactly mean?
> > > > >
> > > > > It means Postgres can do a reliable backup (a consistent snapshot) of a
> > > > > database without shutting down the database.
> > > >
> > > > Hmmm.  My backup procedure, based on earlier discussions in this group,
> > > > involves blocking all write-access during a pg_dump.  That is effectively
> > > > shutting down the database from my perspective.  Is there a quicker way
> > > > to take a consistent snapshot while still allowing writes?
> > >
> > > With 6.5 and 7.0, pg_dump grabs a consistent snapshot of the database at
> > > the time it starts, and dumps that.  No reason to shut out users.
> >
> >Can other folks confirm that this is no longer a problem?  Are people
> >successfully vacuuming while allowing full read/write access to the db?
> >
> >Regards,
> >Ed Loehr