Обсуждение: pg_start_backup without WAL archiving
Why is it not allowed to call pg_start_backup when WAL archiving is off? Wouldn't this be useful as a discrete file system backup without PITR capability? -- Peter Eisentraut http://developer.postgresql.org/~petere/
On Nov 25, 2007 8:24 AM, Peter Eisentraut <peter_e@gmx.net> wrote: > Why is it not allowed to call pg_start_backup when WAL archiving is off? > Wouldn't this be useful as a discrete file system backup without PITR > capability? Because a file system level backup is no good unless the database is stopped, or you are using PITR.
Jeff Larsen wrote: > On Nov 25, 2007 8:24 AM, Peter Eisentraut <peter_e@gmx.net> wrote: > > Why is it not allowed to call pg_start_backup when WAL archiving is off? > > Wouldn't this be useful as a discrete file system backup without PITR > > capability? > > Because a file system level backup is no good unless the database is > stopped, or you are using PITR. You are begging the question. If I enable WAL archiving, make a base backup to a safe place, and my data center goes up in flame immediately afterwards without a WAL segment being archived, that base backup should still be usable. Or maybe not. That's the question. -- Peter Eisentraut http://developer.postgresql.org/~petere/
Peter Eisentraut <peter_e@gmx.net> writes:
> Jeff Larsen wrote:
>> Because a file system level backup is no good unless the database is
>> stopped, or you are using PITR.
> You are begging the question. If I enable WAL archiving, make a base backup
> to a safe place, and my data center goes up in flame immediately afterwards
> without a WAL segment being archived, that base backup should still be
> usable. Or maybe not. That's the question.
And the answer is still "no". If you don't have the entire series of
WAL files made over the period of the base backup, you're out of luck.
regards, tom lane
On Sun, 2007-11-25 at 15:24 +0100, Peter Eisentraut wrote: > Why is it not allowed to call pg_start_backup when WAL archiving is off? > Wouldn't this be useful as a discrete file system backup without PITR > capability? I'm submitting a patch today that better describes PITR facilities for making a standalone backup. -- Simon Riggs 2ndQuadrant http://www.2ndQuadrant.com