On Monday, August 11, 2003 17:26, [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] wrote: >From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] >Sent: Monday, August 11, 2003 17:26 >To: [EMAIL PROTECTED] >Subject: Re: [ADMIN] Backup routine > > >In article <[EMAIL PROTECTED]>, >Bruce Momjian <[EMAIL PROTECTED]> wrote: >>Also, I assume you have to stop the server just for a moment while you >>do the freeze, right? > >It depends on if you need known state or just consistent state. > >Taking a snapshot of the system will get you a consistent >state just like >if the machine crashed. You can restore that snapshot, bring >PG back up >and everything will work. Of course, you really have no way of knowing >what transactions were commited and what were not. > >On the other hand, stop the server/snapshot/start the server >gives you not >only consistency, but a known state. That is, you know for sure that >whatever was done before you stopped the server is what was done. > But these considerations apply to pg_dump-s as well, no? I guess with pg_dump you CAN dump one database at a time, and you can "quiesce" each database before dumping -- disallow connections to that database for the duration of the pg_dump, and wait for all transactions to complete before starting pg_dump -- which is a little more flexible. Given the time it takes to do a pg_dump on databases over a few gigabytes in size, though, I can't say I find the flexibility valuable.
Cheers, Murthy ---------------------------(end of broadcast)--------------------------- TIP 6: Have you searched our list archives? http://archives.postgresql.org