"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