Re: pg_dump --with-* options

On Thu, Jun 12, 2025 at 1:36 PM Robert Haas <robertmhaas@gmail.com> wrote:

> On Thu, Jun 12, 2025 at 11:58 AM Jeff Davis <pgsql@j-davis.com> wrote:
> > On Thu, 2025-06-12 at 09:52 -0500, Nathan Bossart wrote:
> > > If the idea is to remove all options for default behavior, we'd be
> > > removing
> > > --no-statistics, --with-data, and --with-schema at this point.
> >
> > That's OK with me.
>
> Same.
>
> > >   Maybe we
> > > could go a step further and even rip out --statistics-only (in favor
> > > of
> > > --no-schema --no-data --with-statistics).
> >
> > I'd probably keep --statistics-only.
>
> I'm going to vote for removing it. pg_dump has a lot of options, and
> it doesn't seem like a good bet to me to have options that are
> equivalent to various combinations of other options. I don't see any
> particular reason to believe that --statistics-only is even a
> particularly likely combination of options for someone to want. I'd
> rather keep it simple.
>

The use case for --statistics-only is to extract the existing statistics
for the tables and indexes that are involved in a given query that is
giving you problems, allowing you to apply those statistics to an existing
QA/dev database and tweak them without further impacting operations on the
production database. I think this will prove to be very useful, and having
a --statistics-only flag conveys the clear intent of "I want the stats, and
only the stats",



>
> --
> Robert Haas
> EDB: http://www.enterprisedb.com
>
>
If we're hot to remove options, how about we remove the sections flags?
Their utility is reliant upon the user understanding exactly which things
go in which section, and further assumes that everything deterministically
goes in exactly one section, which is no longer the case as Jeff
pointed out recently. They have outlived their usefulness.

If we have the full complement of -no-something flags, and the three -only
flags, we wouldn't need the --with-something flags. That would mean making
statistics export the default on dumps, which I think it should be anyway,
because there's nothing else that we don't dump by default, and while it
might seem strange to have them by default now, NOT having them by default
will feel very strange a few years down the road.