Re: mixed, named notation support

On Aug 6, 2009, at 7:12 PM, Robert Haas wrote:

> On Thu, Aug 6, 2009 at 7:10 PM, Tom Lane<tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
>> Bernd Helmle <mailings(at)oopsware(dot)de> writes:
>>> Here again a patch version with updated documentation. I will stop
>>> reviewing this patch now and mark this ready for committer, so we
>>> have some
>>> time left to incorporate additional feedback.
>>
>> I'm starting to look at this now, and my very first reaction was
>> "what in the world is a leaky list?". I'm not sure I like the
>> data structure itself, but the terminology is certainly completely
>> unhelpful. Can't you come up with something better than
>> "continuous/leaky"?
>
> Stepping back a bit, are we sure this is a feature we even want to
> support? It was already pointed out in the thread on "Parser's hook
> based on funccall" that SQL:201x may standardize => for this purpose.
> I realize that's a problem because of the possibility of a
> user-defined operator named =>, but aren't we usually reluctant to
> adopt syntax that is thought likely to be incompatible with current or
> future SQL standards?

As a "newbie" to postgresql, I would hope this is a feature that will
be supported in the not too distant future. If the standard seems to
be moving in the direction of using 'name => value' as the syntax, it
does seem like that would be the way we would want to go. If I
remember correctly, the main argument for using "value AS name" was
that it wouldn't conflict with current operators AND it would be the
most likely way the standard body would go. (There was a long thread
back in Dec 08 regarding the syntax that can be referenced if someone
wants to read through all of them.)

If it looks like the SQL standard will be going the direction of 'name
=> value', why would we go opposite that?

Either way, I think Pavel has proven that it is easy to adjust his
patch to support either syntax if a decision is made.

-Steve