Re: Multi column range partition table

On Sun, Jul 9, 2017 at 1:12 PM, Dean Rasheed <dean(dot)a(dot)rasheed(at)gmail(dot)com> wrote:
> On 6 July 2017 at 22:43, Joe Conway <mail(at)joeconway(dot)com> wrote:
>> I agree we should get this right the first time and I also agree with
>> Dean's proposal, so I guess I'm a +2
>>
>
> On 7 July 2017 at 03:21, Amit Langote <Langote_Amit_f8(at)lab(dot)ntt(dot)co(dot)jp> wrote:
>> +1 to releasing this syntax in PG 10.
>>
>
> So, that's 3 votes in favour of replacing UNBOUNDED with
> MINVALUE/MAXVALUE for range partition bounds in PG 10. Not a huge
> consensus, but no objections either. Any one else have an opinion?
>

+ <para>
+ Also note that some element types, such as <literal>timestamp</>,
+ have a notion of "infinity", which is just another value that can
+ be stored. This is different from <literal>MINVALUE</> and
+ <literal>MAXVALUE</>, which are not real values that can be stored,
+ but rather they are ways of saying the value is unbounded.
+ <literal>MAXVALUE</> can be thought of as being greater than any
+ other value, including "infinity" and <literal>MINVALUE</> as being
+ less than any other value, including "minus infinity". Thus the range
+ <literal>FROM ('infinity') TO (MAXVALUE)</> is not an empty range; it
+ allows precisely one value to be stored &mdash; the timestamp
+ "infinity".
</para>

The description in this paragraph seems to be attaching intuitive
meaning of word "unbounded" to MAXVALUE and MINVALUE, which have
different intuitive meanings of themselves. Not sure if that's how we
should describe MAXVALUE/MINVALUE.

Most of the patch seems to be replacing "content" with "kind",
RangeDatumContent with PartitionRangeDatumKind and RANGE_DATUM_FINITE
with PARTITION_RANGE_DATUM_VALUE. But those changes in name don't seem
to be adding much value to the patch. Replacing RANGE_DATUM_NEG_INF
and RANGE_DATUM_POS_INF with PARTITION_RANGE_DATUM_MINVALUE and
PARTITION_RANGE_DATUM_MAXVALUE looks like a good change in line with
MINVALUE/MAXVALUE change. May be we should reuse the previous
variables, enum type name and except those two, so that the total
change introduced by the patch is minimal.

--
Best Wishes,
Ashutosh Bapat
EnterpriseDB Corporation
The Postgres Database Company