Re: Deprecating, and scheduling removal of, pg_dump's tar format.

Hi,

On 2018-07-27 12:51:17 -0400, Robert Haas wrote:
> On Thu, Jul 26, 2018 at 11:46 PM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
> > Andres Freund <andres(at)anarazel(dot)de> writes:
> >> Is there any real reason to retain it?
> >
> > As I recall, the principal argument for having it to begin with was
> > that it's a "non proprietary" format that could be read without any
> > PG-specific tools. Perhaps the directory format could be said to
> > serve that purpose too, but if you were to try to collapse a directory
> > dump into one file for transportation, you'd have ... a tar dump.
> >
> > I think a more significant question is what we'd get by removing it?
> > If you want to look around for features that are slightly less used
> > than other arguably-equivalent things, we must have hundreds of those.
> > Doesn't mean that those features have no user constituency.
>
> Yeah. I don't mind removing really marginal features to ease
> maintenance, but I'm not sure that this one is all that marginal or
> that we'd save that much maintenance by eliminating it.

My point is more that it forces users to make choices whenever they use
pg_dump. And the tar format has plenty downsides that aren't immediately
apparent. By keeping something with only a small upside around, we
force users to waste time.

> Why did we invent "custom" format dumps instead of using a standard
> container-file format like tar/cpio/zip/whatever?

Because they're either not all that simple, or don't random read access
inside. But that's just a guess, not fact.

Greetings,

Andres Freund