Re: [HACKERS] Re: [COMMITTERS] pgsql: Use MINVALUE/MAXVALUE insteadof UNBOUNDED for range partition b

On 8 August 2017 at 19:22, Robert Haas <robertmhaas@gmail.com> wrote:
> On Fri, Jul 21, 2017 at 4:24 AM, Dean Rasheed <dean.a.rasheed@gmail.com> wrote:
>> Also drop the constraint prohibiting finite values after an unbounded
>> column, and just document the fact that any values after MINVALUE or
>> MAXVALUE are ignored. Previously it was necessary to repeat UNBOUNDED
>> multiple times, which was needlessly verbose.
>
> I would like to (belatedly) complain about this part of this commit.
> Now you can do stuff like this:
>
> rhaas=# create table foo (a int, b text) partition by range (a, b);
> CREATE TABLE
> rhaas=# create table foo1 partition of foo for values from (minvalue,
> 0) to (maxvalue, 0);
> CREATE TABLE
>
> The inclusion of 0 has no effect, but it is still stored in the
> catalog, shows up in \d foo1, and somebody might think it does
> something.  I think we should go back to requiring bounds after
> minvalue or maxvalue to be minvalue or maxvalue.

Well perhaps verbosity-reduction isn't sufficient justification but I
still think this is correct because logically any values in the bound
after MINVALUE/MAXVALUE are irrelevant, so it seems overly restrictive
to force all later values to be MINVALUE/MAXVALUE when the code will
just ignore those values.

I don't think we should allow values after MINVALUE/MAXVALUE to be
omitted altogether because we document multi-column ranges as being
most easily understood according to the rules of row-wise comparisons,
and they require equal numbers of values in each row.