On Sep 16, 2011, at 11:11 AM, Tom Lane wrote:
> "Caleb Welton" <Caleb.Welton@emc.com> writes:
>> statements such as:
>> PREPARE p1(anyelement) AS SELECT quote_literal($1);
>> PREPARE p2(internal) AS SELECT int2recv($1);
>> Should not be allowed.
>=20
> Hmm. It would require an extra catalog lookup per parameter to enforce
> that. Not sure that it's worth it just to prevent "peculiar" errors.
> Can you point to any worse consequences?
>=20
> regards, tom lane
I haven't found any more severe issues and I'll agree its not a high priori=
ty item. But the fix is simple enough that I don't see a reason to ignore =
it either.
The easiest fix would be, as you say, adding one extra syscache lookup:
static Query *
transformPrepareStmt(ParseState *pstate, PrepareStmt *stmt)
{
...
foreach(l, stmt->argtypes)
{
TypeName *tn =3D lfirst(l);
Oid toid =3D typenameTypeId(pstate, tn);
> /* Pseudotypes are not valid parameters to PREPARE */
> if (get_typtype(toid) =3D=3D TYPTYPE_PSEUDO)
> {
> ereport(ERROR,
> (errcode(ERRCODE_INDETERMINATE_DATATYPE),
> errmsg("type \"%s\" is not a valid parameter for PREPARE",
> TypeNameToString(tn))));
> }
argtoids[i++] =3D toid;
}
...
}
If you really don't like the extra syscache lookup I'd offer two alternativ=
e implementations:
1) Creating a new macro IsPseudoType() like the existing IsPolymorphicType(=
) macro given that we already have the oid.
2) TypenameGetTypid already has the whole cache tuple which contains both t=
he pieces of information we want, but it only returns the oid... easy enoug=
h to fix, but larger api impact.
Regards,
Caleb
