My Object able solution.....??

Here is my short hack for the object reference ( tuple ) return
as int4 function.

Datum spycastoid(PG_FUNCTION_ARGS);
Datum spycastoidbyname(PG_FUNCTION_ARGS);

/* Composite types */

PG_FUNCTION_INFO_V1(spycastoid);

Datum
spycastoid(PG_FUNCTION_ARGS)
{
TupleTableSlot *t = (TupleTableSlot *) PG_GETARG_POINTER(0);
int32 slot = PG_GETARG_INT32(1);
int32 myid;

bool isnull;
myid = DatumGetInt32(GetAttributeByNum(t, slot, &isnull));
if (isnull)
PG_RETURN_INT32(0);

PG_RETURN_INT32(myid);
}

PG_FUNCTION_INFO_V1(spycastoidbyname);

Datum
spycastoidbyname(PG_FUNCTION_ARGS)
{
TupleTableSlot *t = (TupleTableSlot *) PG_GETARG_POINTER(0);
text *slot = PG_GETARG_TEXT_P(1);
int32 myid;
bool isnull;

/*printf( "cast -->%s<----", slot+VARHDRSZ );*/

myid = DatumGetInt32(GetAttributeByName(t, slot->vl_dat, &isnull));
if (isnull)
PG_RETURN_INT32(0);

PG_RETURN_INT32(myid);
}

***************FUNCTION A******************************
CREATE FUNCTION spycastoid( table_has_other_object, int4) RETURNS int4
AS '/usr/lib/postgresql/lib/castfunc.so'
LANGUAGE 'c';

***************FUNCTION A2******************************
CREATE FUNCTION castoid(table_has_other_object) RETURNS int4
AS 'select spycastoid($1, 1);' <---colnum
LANGUAGE 'sql';

***************FUNCTION B******************************
CREATE FUNCTION spycastoidbyname( table_has_other_object , text) RETURNS int4
AS '/usr/lib/postgresql/lib/castfunc.so'
LANGUAGE 'c';

***************FUNCTION B2*****************************
CREATE FUNCTION spycastoidbyname( table_has_other_object ) RETURNS int4
AS 'select spycastoidbyname( $1, \'colname\')'
LANGUAGE 'sql';

so now at lease you can do

select * from child where spycastoid(child, 1)=178120 or preset A2
select * from child where spycastoid(child)=178120
select * from child where spycastoidbyname(child, 'myfather')=178120 or preset B2
select * from child where spycastoidbyname( child )=178120

There may be some bug in between. I'm not sure. When the tuple get by name,
something the string compare is not correct. Let me know if that work.
I really want to see some real object action in PostgreSQL
I'm currently building a Java API for all database to enable object-relation
mapping for rapid application development. Let me know if you want to talk
about this also.

Alex