"Hiroshi Inoue" <Inoue(at)tpf(dot)co(dot)jp> writes:
> What I have minded is e.g. the following case.
> Undoubtedly the page is corrupted(too big offset number).
> I'm suspicious if other pages are safe under such a situation.
You have a point, but I still don't like slowing down PageGetItem.
How about this instead: whenever we read in a page, check to see
if its page header data is sane. We could do this right after the
smgrread call in ReadBufferInternal, and follow the "status = SM_FAIL"
exit path if we see trouble.
regards, tom lane