Bruce Momjian <pgman@candle.pha.pa.us> writes:
>> How is "switch a WAL" an essential component of that scheme? You can
>> archive the latest active segment just as well.
> Ah, but that will be over-written later, so you have to store it
> somewhere safe, rather than just forcing closure of the current
> WAL file and forcing an archive of it.
So? I still don't see the operational benefit.
If you are running a true PITR operation, that is you are archiving off
the complete WAL sequence, then forced WAL switches aren't buying you
anything except wasted archive space. You're still going to want to
archive the active segment when it's done.
If you're not really doing PITR but just want to use a filesystem-level
backup, then you can copy the last WAL segment when you're done whether
it's still active or not.
I honestly think that WAL-switching is a solution in search of a
problem.
regards, tom lane