Re: [HACKERS] Custom compression methods

Hi!

On Mon, Jul 2, 2018 at 3:56 PM Ildus Kurbangaliev
<i(dot)kurbangaliev(at)postgrespro(dot)ru> wrote:
> On Mon, 18 Jun 2018 17:30:45 +0300
> Ildus Kurbangaliev <i(dot)kurbangaliev(at)postgrespro(dot)ru> wrote:
>
> > On Tue, 24 Apr 2018 14:05:20 +0300
> > Alexander Korotkov <a(dot)korotkov(at)postgrespro(dot)ru> wrote:
> >
> > >
> > > Yes, this patch definitely lacks of good usage example. That may
> > > lead to some misunderstanding of its purpose. Good use-cases
> > > should be shown before we can consider committing this. I think
> > > Ildus should try to implement at least custom dictionary compression
> > > method where dictionary is specified by user in parameters.
> > >
> >
> > Hi,
> >
> > attached v16 of the patch. I have splitted the patch to 8 parts so now
> > it should be easier to make a review. The main improvement is zlib
> > compression method with dictionary support like you mentioned. My
> > synthetic tests showed that zlib gives more compression but usually
> > slower than pglz.
> >
>
> I have noticed that my patch is failing to apply on cputube. Attached a
> rebased version of the patch. Nothing have really changed, just added
> and fixed some tests for zlib and improved documentation.

I'm going to review this patch. Could you please rebase it? It
doesn't apply for me due to changes made in src/bin/psql/describe.c.

patching file src/bin/psql/describe.c
Hunk #1 FAILED at 1755.
Hunk #2 FAILED at 1887.
Hunk #3 FAILED at 1989.
Hunk #4 FAILED at 2019.
Hunk #5 FAILED at 2030.
5 out of 5 hunks FAILED -- saving rejects to file src/bin/psql/describe.c.rej

Also, please not that PostgreSQL 11 already passed feature freeze some
time ago. So, please adjust your patch to expect PostgreSQL 12 in the
lines like this:

+ if (pset.sversion >= 110000)

------
Alexander Korotkov
Postgres Professional: http://www.postgrespro.com
The Russian Postgres Company