Re: Adding support for Default partition in partitioning

On 09.05.2017 09:19, Rahila Syed wrote:
> +1 for AS DEFAULT syntax if it helps in improving readability 
> specially in following case
>
> CREATE TABLE p1 PARTITION OF test AS DEFAULT PARTITION BY LIST(a);
>
> Thank you,
> Rahila Syed
>
> On Tue, May 9, 2017 at 1:13 AM, Robert Haas <robertmhaas@gmail.com 
> <mailto:robertmhaas@gmail.com>> wrote:
>
>     On Thu, May 4, 2017 at 4:40 PM, Sven R. Kunze <srkunze@mail.de
>     <mailto:srkunze@mail.de>> wrote:
>     > It yields
>     >
>     > CREATE TABLE p1 PARTITION OF test DEFAULT PARTITION BY LIST(b);
>     >
>     > This reads to me like "DEFAULT PARTITION".
>     >
>     > I can imagine a lot of confusion when those queries are
>     encountered in the
>     > wild. I know this thread is about creating a default partition
>     but I were to
>     > propose a minor change in the following direction, I think
>     confusion would
>     > be greatly avoided:
>     >
>     > CREATE TABLE p1 PARTITION OF test AS DEFAULT PARTITIONED BY LIST(b);
>     >
>     > I know it's a bit longer but I think those 4 characters might serve
>     > readability in the long term. It was especially confusing to see
>     PARTITION
>     > in two positions serving two different functions.
>
>     Well, we certainly can't make that change just for default partitions.
>     I mean, that would be non-orthogonal, right?  You can't say that the
>     way to subpartition is to write "PARTITION BY strategy" when the table
>     unpartitioned or is a non-default partition but "PARTITIONED BY
>     strategy" when it is a default partition.  That would certainly not be
>     a good way of confusing users less, and would probably result in a
>     variety of special cases in places like ruleutils.c or pg_dump, plus
>     some weasel-wording in the documentation.  We COULD do a general
>     change from "CREATE TABLE table_name PARTITION BY strategy" to "CREATE
>     TABLE table_name PARTITIONED BY strategy".  I don't have any
>     particular arguments against that except that the current syntax is
>     more like Oracle, which might count for something, and maybe the fact
>     that we're a month after feature freeze.  Still, if we want to change
>     that, now would be the time; but I favor leaving it alone.
>

You are definitely right. Changing it here would require to change it 
everywhere AND thus to loose syntax parity with Oracle.

I am not in a position to judge this properly whether this would be a 
huge problem. Personally, I don't have an issue with that. But don't 
count me as most important opion on this.

>
>     So I guess I'm still in favor of the CREATE TABLE p1 PARTITION OF test
>     DEFAULT syntax, but if it ends up being AS DEFAULT instead, I can live
>     with that.
>

Is to make it optional an option?

Sven