Re: PG 16 draft release notes ready

On Thu, May 18, 2023 at 3:52 PM Bruce Momjian <bruce(at)momjian(dot)us> wrote:
> So, I looked at this and the problem is that this is best as a single
> release note entry because we are removing and adding, and if I moved it
> to compatibility, I am concerned the new feature will be missed. Since
> WAL inspection is a utility operation, inn general, I think having it in
> the pg_walinspect section makes the most sense.

I don't understand what you mean by that. The changes to
*_till_end_of_wal() (the way that those duplicative functions were
removed, and more permissive end_lsn behavior was added) is unrelated
to all of the other changes. Plus it's just not very important.

> Okay, I went with:
>
> Improve descriptions of pg_walinspect WAL record descriptions
> (Melanie Plageman, Peter Geoghegan)
>
> > Note also that the item "Add pg_waldump option --save-fullpage to dump
> > full page images (David Christensen)" is tangentially related to
> > pg_get_wal_block_info(), since you can also get FPIs using
> > pg_get_wal_block_info() (in fact, that was originally its main
> > purpose). I'm not saying that you necessarily need to connect them
> > together in any way, but you might consider it.
>
> Well, there is so much _new_ in that tool that listing everything new
> seems confusing.

There is pretty much one truly new piece of functionality added to
pg_walinspect (the function called pg_get_wal_block_info was added) --
since the enhancement to rmgr description output applies equally to
pg_waldump, no matter where you place it in the release notes. So not
sure what you mean.

> All changes committed.

Even after these changes, the release notes still refer to a function
called "pg_get_wal_block". There is no such function, though -- not in
Postgres 16, and not in any other major version.

As I said, there is a new function called "pg_get_wal_block_info". It
should simply be presented as a whole new function that offers novel
new functionality compared to what was available in Postgres 15 --
without any further elaboration. (It happens to be true that
pg_get_wal_block_info only reached its final form following multiple
rounds of work in multiple commits, but that is of no consequence to
users -- even the earliest form of the function appeared in a commit
in the Postgres 16 cycle.)

--
Peter Geoghegan