Bruce Momjian <pgman@candle.pha.pa.us> writes:
> I was thinking of just throwing the inactive page number into WAL. Much
> smaller than the entire page image. You don't touch the page. Does
> that help?
I don't think so. Somehow you have to tell the other backends that that
page is dead; merely recording it in WAL doesn't do that.
More to the point, you can't recycle (overwrite) that page until you've
checkpointed or WAL-logged the replacement page; so you still end up
with disk I/O for the replacement.
regards, tom lane