Re: PITR Functional Design v2 for 7.5 - Mailing list pgsql-hackers

From Tom Lane
Subject Re: PITR Functional Design v2 for 7.5
Date
Msg-id 6549.1078931047@sss.pgh.pa.us
Whole thread Raw
In response to Re: PITR Functional Design v2 for 7.5  (Andreas Pflug <pgadmin@pse-consulting.de>)
Responses Re: PITR Functional Design v2 for 7.5
List pgsql-hackers
Andreas Pflug <pgadmin@pse-consulting.de> writes:
> To clarify:
> I'd expect a cluster to be workable, if I
> - disable VACUUM until backup completed
> - issue CHECKPOINT
> - backup clog (CHECKPOINT and backup clog are the "backup checkpoint")
> - backup all datafiles (which include at least all completed transaction 
> data at checkpoint time)
> and then
> - restore datafiles and clog
> - bring up pgsql.

Why is that a useful approach?  You might as well shut down the
postmaster and do a cold filesystem backup, because you are depending on
the data files (including clog) not to change after the checkpoint.  You
cannot make such an assumption in a running database.

Preventing VACUUM does not help btw.
        regards, tom lane


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