Re: First draft of the PG 15 release notes - Mailing list pgsql-hackers

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,
JeevanLadhe)
 
> > > > 2. Allow pg_basebackup's --compress option to control the compression method and options (Michael Paquier,
RobertHaas)
 
> > > >    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@momjian.us>        https://momjian.us
  EDB                                      https://enterprisedb.com

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