Re: [HACKERS] Custom compression methods

On Sat, Mar 20, 2021 at 1:22 PM Dilip Kumar <dilipbalaut(at)gmail(dot)com> wrote:
>
> On Sat, Mar 20, 2021 at 8:11 AM Robert Haas <robertmhaas(at)gmail(dot)com> wrote:
> >
> > On Fri, Mar 19, 2021 at 8:25 PM Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
> > > Extrapolating from the way we've dealt with similar issues
> > > in the past, I think the structure of pg_dump's output ought to be:
> > >
> > > 1. SET default_toast_compression = 'source system's value'
> > > in among the existing passel of SETs at the top. Doesn't
> > > matter whether or not that is the compiled-in value.
> > >
> > > 2. No mention of compression in any CREATE TABLE command.
> > >
> > > 3. For any column having a compression option different from
> > > the default, emit ALTER TABLE SET ... to set that option after
> > > the CREATE TABLE. (You did implement such a SET, I trust.)
> >
> > Actually, *I* didn't implement any of this. But ALTER TABLE sometab
> > ALTER somecol SET COMPRESSION somealgo works.
> >
> > This sounds like a reasonable approach.
>
> The attached patch implements that.

After sending this, just saw Justin also included patches for this. I
think the ALTER ..SET COMPRESSION is more or less similar, I just
fetched it from the older version of the patch set. But SET
default_toast_compression are slightly different. I will look into
your version and provide my opinion on which one looks better and we
can commit that and feel free to share your thoughts.

--
Regards,
Dilip Kumar
EnterpriseDB: http://www.enterprisedb.com