Re: page corruption on 8.3+ that makes it to standby

I wrote:
>>> I think it is appropriate to be setting the LSN/TLI in the case of a
>>> page that's been constructed by the caller as part of the WAL-logged
>>> action, but doing so in copy_relation_data seems rather questionable.

BTW, I thought of an argument that explains why that's sane: it marks
the copied page as having been recently WAL-logged. If we do some
action on the copied relation shortly after completing the
copy_relation_data transaction, we will see that its LSN is later than
the last checkpoint and know that we don't need to emit a full-page WAL
image for it, which is correct because in case of crash+restart the
HEAP_NEWPAGE record will provide the full-page image. If we left the
source relation's page's LSN in there, we would frequently make the
wrong decision and emit an unnecessary extra full-page image.

So nevermind that distraction. I'm back to thinking that fix1 is
the way to go.

regards, tom lane