Re: Extracting cross-version-upgrade knowledge from buildfarm client

I wrote:
> OK, I'll take a look at that and make a new draft.

Here's version 2, incorporating your suggestions and with some
further work to make it handle 9.2 fully. I think this could
be committable so far as HEAD is concerned, though I still
need to make versions of AdjustUpgrade.pm for the back branches.

I tried to use this to replace upgrade_adapt.sql, but failed so
far because I couldn't figure out exactly how you're supposed
to use 002_pg_upgrade.pl with an old source installation.
It's not terribly well documented. In any case I think we
need a bit more thought about that, because it looks like
002_pg_upgrade.pl thinks that you can supply any random dump
file to serve as the initial state of the old installation;
but neither what I have here nor any likely contents of
upgrade_adapt.sql or the "custom filter" rules are going to
work on databases that aren't just the standard regression
database(s) of the old version.

I assume we should plan on reverting 9814ff550 (Add custom filtering
rules to the TAP tests of pg_upgrade)? Does that have any
plausible use that's not superseded by this patchset?

regards, tom lane