Horton

Thread

Commits

  1. Fix format_type() to restore its old behavior.

  2. Refactor format_type APIs to be more modular

  1. change in behaviour for format_type() call

    Rushabh Lathia <rushabh.lathia@gmail.com> — 2018-03-01T10:16:12Z

    Commit a26116c6cbf4117e8efaa7cfc5bacc887f01517f changed the behaviour
for format_type.

Prior to commit, format_type() used to set typemod_given to false for
typemode = NULL.

format_type()
..
if (PG_ARGISNULL(1))
result = format_type_internal(type_oid, -1, false, true, false);
else
{
typemod = PG_GETARG_INT32(1);
result = format_type_internal(type_oid, typemod, true, true, false);
}
..

With the commit format_type() always set the FORMAT_TYPE_TYPEMOD_GIVEN
flag even when typemode is NULL (-1).

Below are the difference it's making to the query output:

Before commit:

postgres@95320=#select format_type('bpchar'::regtype, null);
 format_type
-------------
 character
(1 row)

postgres@95320=#select format_type('bit'::regtype, null);
 format_type
-------------
 bit
(1 row)

After commit:

postgres@90169=#select format_type('bpchar'::regtype, null);
 format_type
-------------
 bpchar
(1 row)

postgres@90169=#select format_type('bit'::regtype, null);
 format_type
-------------
 "bit"
(1 row)

Is this expected behaviour? attaching patch to get back the older
behaviour.

Thanks,


Regards,
Rushabh Lathia
www.EnterpriseDB.com

  2. Re: change in behaviour for format_type() call

    Tom Lane <tgl@sss.pgh.pa.us> — 2018-03-01T15:49:44Z

    Rushabh Lathia <rushabh.lathia@gmail.com> writes:
> Commit a26116c6cbf4117e8efaa7cfc5bacc887f01517f changed the behaviour
> for format_type.
> ...
> Is this expected behaviour? attaching patch to get back the older
> behaviour.

I don't see anything in the commit message or linked discussion to
indicate that any visible behavior change was intended, so I think
you're right, this is a bug.  Will check and push your patch.

			regards, tom lane

  3. Re: change in behaviour for format_type() call

    Tom Lane <tgl@sss.pgh.pa.us> — 2018-03-01T16:40:07Z

    I wrote:
> I don't see anything in the commit message or linked discussion to
> indicate that any visible behavior change was intended, so I think
> you're right, this is a bug.  Will check and push your patch.

Actually, this patch still wasn't quite right: although it fixed
one aspect of the behavior, it still produced identical results
for typemod NULL and typemod -1, which as the function's comment
explains is not what should happen.  I tweaked the logic to look
as much as possible like before, and added a regression test.

			regards, tom lane

  4. Re: change in behaviour for format_type() call

    Alvaro Herrera <alvherre@alvh.no-ip.org> — 2018-03-01T17:54:22Z

    Tom Lane wrote:
> I wrote:
> > I don't see anything in the commit message or linked discussion to
> > indicate that any visible behavior change was intended, so I think
> > you're right, this is a bug.  Will check and push your patch.
> 
> Actually, this patch still wasn't quite right: although it fixed
> one aspect of the behavior, it still produced identical results
> for typemod NULL and typemod -1, which as the function's comment
> explains is not what should happen.  I tweaked the logic to look
> as much as possible like before, and added a regression test.

Thanks!

-- 
Álvaro Herrera                https://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services

  5. Re: change in behaviour for format_type() call

    Michael Paquier <michael@paquier.xyz> — 2018-03-02T04:01:19Z

    On Thu, Mar 01, 2018 at 02:54:22PM -0300, Alvaro Herrera wrote:
> Tom Lane wrote:
>> Actually, this patch still wasn't quite right: although it fixed
>> one aspect of the behavior, it still produced identical results
>> for typemod NULL and typemod -1, which as the function's comment
>> explains is not what should happen.  I tweaked the logic to look
>> as much as possible like before, and added a regression test.
> 
> Thanks!

Thanks Tom.  Yes, we focused on not changing any existing behavior with
this patch.  So this report was a bug.
--
Michael

  6. Re: change in behaviour for format_type() call

    Rushabh Lathia <rushabh.lathia@gmail.com> — 2018-03-02T05:10:55Z

    On Thu, Mar 1, 2018 at 10:10 PM, Tom Lane <tgl@sss.pgh.pa.us> wrote:

> I wrote:
> > I don't see anything in the commit message or linked discussion to
> > indicate that any visible behavior change was intended, so I think
> > you're right, this is a bug.  Will check and push your patch.
>
> Actually, this patch still wasn't quite right: although it fixed
> one aspect of the behavior, it still produced identical results
> for typemod NULL and typemod -1, which as the function's comment
> explains is not what should happen.  I tweaked the logic to look
> as much as possible like before, and added a regression test.
>

Thanks Tom.


Regards,
Rushabh Lathia
www.EnterpriseDB.com