RE: v12 and pg_restore -f-

Hi,

On Sun, Oct 6, 2019 at 7:09 PM, Justin Pryzby wrote:
> I saw this and updated our scripts with pg_restore -f-
> https://www.postgresql.org/docs/12/release-12.html
> |In pg_restore, require specification of -f - to send the dump contents to standard output (Euler Taveira)
> |Previously, this happened by default if no destination was specified, but that was deemed to be unfriendly.
>
> What I didn't realize at first is that -f- has no special meaning in v11 - it
> just writes a file called ./- And it's considered untennable to change
behavior of v11.

Ahh... I totally missed thinking about the behavior of "-f -" in v11 when I reviewed this patch.

On Wed, Oct 9, 2019 at 0:45 PM, Stephen Frost wrote:
> * Euler Taveira (euler(at)timbira(dot)com(dot)br) wrote:
> > Em ter, 8 de out de 2019 às 15:08, Stephen Frost <sfrost(at)snowman(dot)net> escreveu:
> > > * Tom Lane (tgl(at)sss(dot)pgh(dot)pa(dot)us) wrote:
> > > > Andrew Gierth <andrew(at)tao11(dot)riddles(dot)org(dot)uk> writes:
> > > > > "Tom" == Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> writes:
> > > > > Tom> Perhaps we could change the back branches so that they
> > > > > interpret Tom> "-f -" as "write to stdout", but without
> > > > > enforcing that you use Tom> that syntax.
> > > >
> > > > > We should definitely do that.
> > >
> > > I agree that this would be a reasonable course of action. Really,
> > > it should have always meant that...
> > >
> > Indeed, it was a broken behavior and the idea was to fix it. However,
> > changing pg_restore in back-branches is worse than do nothing because
> > it could break existent scripts.
>
> I can certainly respect that argument, in general, but in this specific case, I've got a really hard time believeing
> that people wrote scripts which use '-f -' with the expectation that a './-' file was to be created.

+1.

If we only think of the problem that we can't use "-f -" with the meaning "dump to the stdout" in v11 and before ones, it seems a bug and we should fix it.
Of course, if we fix it, some people would go into the trouble, but such people are who wrote scripts which use '-f -' with the expectation that a './-' file.
I don't think there are such people a lot.

--
Yoshikazu Imai