Обсуждение: question about pg_dump
Hi everyone,
I have a question about pg_dump backups. Will changes made in the database made during a pg_dump operation be reflected in the dumped datafile? Or is the data the exact dataset that was in the database as of the start of the backup?
From what I understand of the documentation, any changes made during the backup would NOT be in the dumped datafile. That is very important for a monthend process where I need consistent data as of exactly the time the dump starts, which is why I’m confirming that is indeed the case.
Thanks,
Scot Kreienkamp
skreien@la-z-boy.com
Hi everyone,
I have a question about pg_dump backups. Will changes made in the database made during a pg_dump operation be reflected in the dumped datafile? Or is the data the exact dataset that was in the database as of the start of the backup?
--
GJ
2009/10/22 Grzegorz Jaśkiewicz <gryzman@gmail.com>: > > > On Thu, Oct 22, 2009 at 3:42 PM, Scot Kreienkamp <SKreien@la-z-boy.com> > wrote: >> >> Hi everyone, >> >> >> >> I have a question about pg_dump backups. Will changes made in the >> database made during a pg_dump operation be reflected in the dumped >> datafile? Or is the data the exact dataset that was in the database as of >> the start of the backup? > > pg_dump opens transaction, on a serializable isolation level. In short, it > is the proper full isolation level (as oppose to the default one: "read > committed"). It can cause locks up on database, but the idea is that the > dump it self is a snapshot, and is fully atomic. Only DDL type stuff should be locked. Regular updates / inserts / delete should run just fine during a backup.