Re: [doc] remove reference to pg_dump pre-8.1 switch behaviour

Stephen Frost <sfrost@snowman.net> writes:
> We do need to decide at what point we're going to move forward pg_dump's
> oldest server version support.

I'm not really in a big hurry to move it forward at all.  There were
good solid reasons to drop support for pre-schema and pre-pg_depend
servers, because of the messy kluges pg_dump had to implement
to provide only-partial workarounds for those lacks.  But I don't
see comparable reasons or code savings that we'll get from dropping
later versions.

There is an argument for dropping support for server versions that
fail to build anymore with modern toolchains, since once that happens
it becomes difficult to test, unless you have old executables already
laying around.  But I don't think we're at that point yet for 8.0 or
later.  (I rebuilt 7.4 and later when I updated my workstation to
RHEL8 a few months ago, and they seem fine, though I did use -O0 out of
fear of -faggressive-loop-optimizations bugs for anything before 8.2.)

But anyway, this was about documentation not code.  What I'm wondering
about is when to drop things like, say, this bit in the regex docs:

    Two significant incompatibilities exist between AREs and the ERE syntax
    recognized by pre-7.4 releases of <productname>PostgreSQL</productname>:
    (etc etc)

Seems like we could have gotten rid of that by now, but when exactly
does it become fair game?  And can we have a non-ad-hoc process for
getting rid of such cruft?

			regards, tom lane