Thanks for the patch. This is not adding something that users can't do right now, but definitely improves the usability of the pg_waldump as it avoids external filterings. Also, it can give the stats/info at table and block level. So, +1 from my side.
Thanks for the feedback; I will be incorporating most of this into a new version, with a couple of responses below.
3) Crossing 80 char limit
This is neither here nor there, but have we as a project considered increasing that to something more modern? I know a lot of current projects consider 132 to be a more reasonable limit. (Will reduce it down to that for now, but consider this a vote towards increasing that limit.)
5) I would also see a need for "filter by FPW" i.e. list all WAL records with "FPW".
Yes, that wouldn't be too hard to add to this, can add to the next version. We probably ought to also add the fork number as specifiable as well. Other thoughts on could be some wildcard value in the relation part, so `1234/23456/*` could filter WAL to a specific database only, say, or some other multiple specifier, like `--block=1234,123456,121234`. (I honestly consider this to be more advanced than we'd need to support in this patch, but if probably wouldn't be too hard to add to it.)
