Re: PITR, checkpoint, and local relations - Mailing list pgsql-hackers

From Tom Lane
Subject Re: PITR, checkpoint, and local relations
Date
Msg-id 14781.1028318500@sss.pgh.pa.us
Whole thread Raw
In response to Re: PITR, checkpoint, and local relations  ("J. R. Nield" <jrnield@usol.com>)
Responses Re: PITR, checkpoint, and local relations  ("J. R. Nield" <jrnield@usol.com>)
Re: PITR, checkpoint, and local relations  (Richard Tucker <richt@multera.com>)
List pgsql-hackers
"J. R. Nield" <jrnield@usol.com> writes:
> The predicate for files we MUST (fuzzy) copy is: 
>   File exists at start of backup && File exists at end of backup

Right, which seems to me to negate all these claims about needing a
(horribly messy) way to read uncommitted system catalog entries, do
blind reads, etc.  What's wrong with just exec'ing tar after having
done a checkpoint?

(In particular, I *strongly* object to using the buffer manager at all
for reading files for backup.  That's pretty much guaranteed to blow out
buffer cache.  Use plain OS-level file reads.  An OS directory search
will do fine for finding what you need to read, too.)
        regards, tom lane


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