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

Hi

2015-12-21 16:21 GMT+01:00 Artur Zakirov <a(dot)zakirov(at)postgrespro(dot)ru>:

> Hi.
> I have tried to do some review of this patch. Below are my comments.
>
> Introduction:
>
> This patch fixes and adds the following functionality:
> - %TYPE - now can be used for composite types.
> - %ARRAYTYPE - new functionality, provides the array type from a variable
> or table column.
> - %ELEMENTTYPE - new funcitonality, provides the element type of a given
> array.
>
> New regression tests are included in the patch. Changes to the
> documentation are not provided.
>
> Initial Run:
>
> The patch applies correctly to HEAD. Regression tests pass successfully,
> without errors. It seems that the patch work as you expected.
>
> Performance:
>
> It seems patch have not possible performance issues for the existing
> functionality.
>
> Coding:
>
> The style looks fine. I attached the patch that does some corrections in
> code and documentation. I have corrected indentation in pl_comp.c and
> "read_datatype" function in pl_gram.y. I think changes in "read_datatype"
> function would be better to avoid a code duplication. But I could be wrong
> of course.
>
> Conclusion:
>
> The patch could be applied on master with documentation corrections. But
> I'm not sure that your task could be resloved only by adding %ARRAYTYPE and
> %ELEMENTTYPE. Maybe you will give some examples?
>

Thank you for review. The changes in code are good idea.

I waited with documentation if there will be some objections to syntax. The
month later, there are not any known objection.

The target of this feature isn't using for storing of database objects
only, but for storing the values of polymorphic parameters.

CREATE OR REPLACE FUNCTION buble_sort(a anyarray)
RETURNS anyarray AS $$
DECLARE
aux a%ELEMENTTYPE;
repeat_again boolean DEFAULT true;
BEGIN
-- Don't use this code for large arrays!
-- use builtin sort
WHILE repeat_again
repeat_again := false;
FOR i IN array_lower(a, 1) .. array_upper(a, 2)
LOOP
IF a[i] > a[i+1] THEN
aux := a[i+1];
a[i+1] := a[i]; a[i] := aux;
repeat_again := true;
END IF;
END LOOP;
END WHILE;
RETURN a;
END;
$$ LANGUAGE plpgsql;

CREATE OR REPLACE FUNCTION array_init(v anyelement, size integer)
RETURNS anyarray AS $$
DECLARE result v%ARRAYTYPE DEFAULT '{}';
BEGIN
-- prefer builtin function array_fill
FOR i IN 1 .. size
LOOP
result := result || v;
END LOOP;
RETURN result;
END;
$$ LANGUAGE plpgsql;

Regards

Pavel

>
> --
> Artur Zakirov
> Postgres Professional: http://www.postgrespro.com
> Russian Postgres Company
>