Re: Identifying no-op length coercions

On Mon, May 23, 2011 at 2:46 PM, Noah Misch <noah(at)leadboat(dot)com> wrote:
> On Mon, May 23, 2011 at 02:11:39PM -0400, Robert Haas wrote:
>> On Mon, May 23, 2011 at 1:53 PM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
>> > Maybe. ?But casts would be the least of our concerns if we were trying
>> > to change the column type. ?Changing typmod doesn't affect the set of
>> > operations that could be applied to a column, whereas changing type
>> > surely does.
>>
>> OK, this is the crucial point I was missing.  Sorry for being a bit
>> fuzzy-headed about this.
>>
>> My mental model of our type system, or of what a type system ought to
>> do, just doesn't match the type system we've got.
>>
>> So let's do it the way you proposed.
>
> Good deal.  Given that conclusion, the other policy decision I anticipate
> affecting this particular patch is the choice of syntax.  Presumably, it will be
> a new common_func_opt_item.  When I last looked at the keywords list and tried
> to come up with something, these were the best I could do:
>
>  CREATE FUNCTION ... PARSER MAPPING helperfunc(args)
>  CREATE FUNCTION ... PLANS CONVERSION helperfunc(args)
>
> Both feel forced, to put it generously.  Any better ideas?  Worth adding a
> keyword to get something decent?

Do you have something specific in mind?

Just to throw out another few possibilities, how about INLINE FUNCTION
or ANALYZE FUNCTION?

--
Robert Haas
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