Ron Johnson <[EMAIL PROTECTED]> writes: > And I strongly dispute the notion that it would only take 3 hours > to dump/restore a TB of data. This seems to point to a downside > of MVCC: this inability to to "page-level" database backups, which > allow for "rapid" restores, since all of the index structures are > part of the backup, and don't have to be created, in serial, as part > of the pg_restore.
If you have a filesystem capable of atomic "snapshots" (Veritas offers this I think), you *should* be able to do this fairly safely--take a snapshot of the filesystem and back up the snapshot. On a restore of the snapshot, transactions in progress when the snapshot happened will be rolled back, but everything that committed before then will be there (same thing PG does when it recovers from a crash). Of course, if you have your database cluster split across multiple filesystems, this might not be doable. Note: I haven't done this, but it should work and I've seen it talked about before. I think Oracle does this at the storage manager level when you put a database in backup mode; doing the same in PG would probably be a lot of work. This doesn't help with the upgrade issue, of course... -Doug ---------------------------(end of broadcast)--------------------------- TIP 2: you can get off all lists at once with the unregister command (send "unregister YourEmailAddressHere" to [EMAIL PROTECTED])