Re: plpgsql - DECLARE - cannot to use %TYPE or %ROWTYPE for composite types

Hi

2016-03-03 0:27 GMT+01:00 Jim Nasby <Jim(dot)Nasby(at)bluetreble(dot)com>:

> On 3/2/16 3:52 PM, Pavel Stehule wrote:
>
>> Right, and it's arguably dubious that that doesn't already work.
>> Unfortunately, these % things are just random plpgsql parser hacks,
>> not
>> real types. Maybe this should be done in the main PostgreSQL parser
>> with parameter hooks, if we wanted this feature to be available
>> outside
>> plpgsql as well.
>>
>>
>> I am not fan to propagate this feature outside PLpgSQL - it is possible
>> new dependency between database object, and the cost is higher than
>> benefits.
>>
>
> I fail to see how it'd be a dependency. I'd expect it to look up the type
> when you run the command, just like plpgsql does. I think it'd be useful to
> have.
>

if we publish this feature to SQL, then somebody can use it in table
definition

CREATE TABLE a(a int);
CREATE TABLE b(a a.a%TYPE)

And the people expecting the living relation between table a and table b.
So when I do ALTER a.a, then b.a should be changed. What if I drop a.a or
drop a?

So this is reason, why I don't would this feature in SQL side.

Regards

Pavel

>
> That said, I think that should be a completely separate patch and
> discussion. Lets at least get it into plpgsql first.
>
> As for the array of element/element of array feature; I agree it would be
> nice, but we're pretty late in the game for that, and I don't see why that
> couldn't be added later.
>
> --
> Jim Nasby, Data Architect, Blue Treble Consulting, Austin TX
> Experts in Analytics, Data Architecture and PostgreSQL
> Data in Trouble? Get it in Treble! http://BlueTreble.com
>