Re: Regarding Checkpoint Redo Record

Robert Haas <robertmhaas@gmail.com> writes:
> But, the OP makes me wonder: why can a standby only perform a
> restartpoint where the master performed a checkpoint?  It seems like a
> standby ought to be able to create a restartpoint anywhere, just by
> writing everything, flushing it to disk, and update pg_control.

Perhaps, but then crash restarts would have to accept start pointers
that point at any random place in the WAL.  I like the additional error
checking of verifying that there's a checkpoint recod there.  Also
I think the full-page-write mechanism would no longer protect against
torn pages during replay if you did that.
        regards, tom lane