Re: First draft of the PG 15 release notes

On Tue, Jul 19, 2022 at 01:13:07PM -0500, Justin Pryzby wrote:
> On Tue, Jul 19, 2022 at 01:24:30PM -0400, Bruce Momjian wrote:
> > Well, I put the --no-synchronized-snapshots item in incompatibilities
> > since it is a user-visible change that might require script adjustments.
> > However, I put the limit of pg_dump to 9.2 and greater into the pg_dump
> > section. Are you suggesting I move the--no-synchronized-snapshots item
> > down there? That doesn't match with the way I have listed other
> > incompatibilities so I am resistant to do that.
>
> I'd rather see the "limit support to v9.2" be moved or added to the
> "incompatibilities" section, maybe with "remove --no-synchronized-snapshots"
> as a secondary sentence.

Is removing support for an older version an incompatibility --- I didn't
think so.

> > > > 0. Add support for LZ4 and Zstandard compression of server-side base backups (Jeevan Ladhe, Robert Haas)
> > > > 1. Allow pg_basebackup to use LZ4 and Zstandard compression on server-side base backup files (Dipesh Pandit, Jeevan Ladhe)
> > > > 2. Allow pg_basebackup's --compress option to control the compression method and options (Michael Paquier, Robert Haas)
> > > > New options include server-gzip (gzip on the server), client-gzip (same as gzip).
> > > > 3. Allow pg_basebackup to compress on the server side and decompress on the client side before storage (Dipesh Pandit)
> > > > This is accomplished by specifying compression on the server side and plain output format.
> > >
> > > I still think these expose the incremental development rather than the
> > > user-facing change.
> >
> > > 1. It seems wrong to say "server-side" since client-side compression with
> > > LZ4/zstd is also supported.
> >
> > Agreed. I changed it to:
> >
> > Allow pg_basebackup to do LZ4 and Zstandard server-side compression
> > on base backup files (Dipesh Pandit, Jeevan Ladhe)
>
> This still misses the point that those compression algs are also supported on
> the client side, so it seems misleading to mention "server-side" support.

I reworked that paragraph in the attached patch. What we did was to add
server-side gzip/LZ/ZSTD, and client-side LZ/ZSTD. (We already had
client-side gzip.) Hopefully the new text is clearer. You can see the
new output here:

https://momjian.us/pgsql_docs/release-15.html

> > > > Allow custom scan provders to indicate if they support projections (Sven Klemm)
> > > > The default is now that custom scan providers can't support projections, so they need to be updated for this release.
> > >
> > > Per the commit message, they don't "need" to be updated.
> > > I think this should say "The default now assumes that a custom scan provider
> > > does not support projections; to retain optimal performance, they should be
> > > updated to indicate whether that's supported.
> >
> > Okay, I went with this text:
> >
> > The default is now that custom scan providers are assumed to not
> > support projections; those that do need to be updated for this
> > release.
>
> I'd say "those that do *will need to be updated" otherwise the sentence can
> sound like it means "those that need to be updated [will] ..."

Oh, good point, done.

Cumulative patch attached.

--
Bruce Momjian <bruce(at)momjian(dot)us> https://momjian.us
EDB https://enterprisedb.com

Indecision is a decision. Inaction is an action. Mark Batterson