Re: refactoring basebackup.c

Hi Everyone,

So, I went ahead and have now also implemented client side decompression
for zstd.

Robert separated[1] the ZSTD configure switch from my original patch
of server side compression and also added documentation related to
the switch. I have included that patch here in the patch series for
simplicity.

The server side compression patch
0002-ZSTD-add-server-side-compression-support.patch has also taken care
of Justin Pryzby's comments[2]. Also, made changes to pg_basebackup help
as suggested by Álvaro Herrera.

[1]
https://www.postgresql.org/message-id/CA%2BTgmobRisF-9ocqYDcMng6iSijGj1EZX99PgXA%3D3VVbWuahog%40mail.gmail.com
[2]
https://www.postgresql.org/message-id/20220215175944.GY31460%40telsasoft.com

Regards,
Jeevan Ladhe

On Wed, 16 Feb 2022 at 21:46, Robert Haas <robertmhaas(at)gmail(dot)com> wrote:

> On Wed, Feb 16, 2022 at 11:11 AM Alvaro Herrera <alvherre(at)alvh(dot)no-ip(dot)org>
> wrote:
> > This is hard to interpret for humans though because of the nested
> > brackets and braces. It gets considerably easier if you split it in
> > separate variants:
> >
> > -Z, --compress=[{client|server}-]{gzip|lz4}[:LEVEL]
> > -Z, --compress=LEVEL
> > -Z, --compress=none
> > compress tar output with given compression
> method or level
> >
> >
> > or, if you choose to leave the level-only variant undocumented, then
> >
> > -Z, --compress=[{client|server}-]{gzip|lz4}[:LEVEL]
> > -Z, --compress=none
> > compress tar output with given compression
> method or level
> >
> > There still are some nested brackets and braces, but the scope is
> > reduced enough that interpreting seems quite a bit simpler.
>
> I could go for that. I'm also just noticing that "none" is not really
> a compression method or level, and the statement that it can only
> compress "tar" output is no longer correct, because server-side
> compression can be used together with -Fp. So maybe we should change
> the sentence afterward to something a bit more generic, like "specify
> whether and how to compress the backup".
>
> --
> Robert Haas
> EDB: http://www.enterprisedb.com
>