Re: merging some features from plpgsql2 project

On Tue, Jan 10, 2017 at 1:03 AM, Jim Nasby <Jim(dot)Nasby(at)bluetreble(dot)com> wrote:

> On 1/9/17 5:53 PM, Marko Tiikkaja wrote:
>
>> My idea was that the currently unsupported combination of NOT
>> NULL and
>> no DEFAULT would mean "has to be assigned to a non-NULL value
>> before it
>> can be read from, or an exception is thrown". Solves the most
>> common
>> use case and is backwards compatible.
>>
>>
>> That won't allow you to use a variable in multiple places though...
>> is there a reason we couldn't support something like IS DEFINED and
>> UNSET?
>>
>>
>> I don't understand what your use case is. Could you demonstrate that
>> with some code you'd write if these features were in?
>>
>
> One use case is NEW and OLD in triggers. Checking to see if one or the
> other is set is easier than checking TG_OP. It's also going to be faster
> (probably MUCH faster; IIRC the comparison currently happens via SPI).
>

This sounds useless.

> Another case is selecting into a record:
>
> EXECUTE ... INTO rec;
> IF rec IS DEFINED THEN
> ELSE
> EXECUTE <something else> INTO rec;
> IF rec IS DEFINED THEN
>

And this a workaround for non-functional FOUND.

I can't get excited about this idea based on these examples.

.m