Re: return query/composite types

On Fri, Feb 20, 2009 at 3:00 PM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
> Merlin Moncure <mmoncure@gmail.com> writes:
>> create table foo(a int, b int);
>> postgres=# create function rfoo() returns setof foo as $$ begin return
>> query select foo from foo; end; $$ language plpgsql;
>
> Use "select * from ..." instead.

Yeah...I was thinking maybe that shouldn't be required:
1. it's illogical and conflicts with regular non 'returns query'
semantics (declare foo, assign, return)
2. if 'foo' is result of set returning function (like unnest), you
need to make extra subquery to prevent that function from executing
lots of extra times.
e.g.
select unnest(foo) from <something> will unnest the set six times if
foo has six fields.  This is a bit of a landmine since type returning
functions are _fairly_ common use for composite types.

These aren't really complaints since the workarounds are trivial, just
casual wondering if the behavior is correct.

merlin