Thread: Schema name of function
Just got reminded... Is there a way for a C function to determine the name of the schema in which is was created? ... John
On Mon, Feb 14, 2005 at 07:32:15PM +1100, John Hansen wrote: > > Is there a way for a C function to determine the name of the > schema in which is was created? Dunno if there's anything as simple as whats_my_schema(), but fcinfo->flinfo->fn_oid should contain the function's oid. If nobody mentions an easier way, you could use SPI to query pg_proc and pg_namespace. -- Michael Fuhr http://www.fuhr.org/~mfuhr/
Michael Fuhr <mike@fuhr.org> writes:
> On Mon, Feb 14, 2005 at 07:32:15PM +1100, John Hansen wrote:
>> Is there a way for a C function to determine the name of the
>> schema in which is was created?
> Dunno if there's anything as simple as whats_my_schema(), but
> fcinfo->flinfo->fn_oid should contain the function's oid. If nobody
> mentions an easier way, you could use SPI to query pg_proc and
> pg_namespace.
In C, it'd be a lot easier (and faster) to do a couple of SearchSysCache
calls than to use SPI to get those rows.
regards, tom lane
On Mon, Feb 14, 2005 at 11:11:53AM -0500, Tom Lane wrote: > > In C, it'd be a lot easier (and faster) to do a couple of SearchSysCache > calls than to use SPI to get those rows. The following appears to work -- does it look right, aside from the missing error checking? tuple = SearchSysCache(PROCOID, ObjectIdGetDatum(fcinfo->flinfo->fn_oid), 0, 0, 0); nsoid = SysCacheGetAttr(PROCOID, tuple, Anum_pg_proc_pronamespace, &isnull); schemaname= get_namespace_name(nsoid); ReleaseSysCache(tuple); -- Michael Fuhr http://www.fuhr.org/~mfuhr/
Michael Fuhr <mike@fuhr.org> writes:
> On Mon, Feb 14, 2005 at 11:11:53AM -0500, Tom Lane wrote:
>> In C, it'd be a lot easier (and faster) to do a couple of SearchSysCache
>> calls than to use SPI to get those rows.
> The following appears to work -- does it look right, aside from the
> missing error checking?
> tuple = SearchSysCache(PROCOID,
> ObjectIdGetDatum(fcinfo->flinfo->fn_oid),
> 0, 0, 0);
> nsoid = SysCacheGetAttr(PROCOID, tuple,
> Anum_pg_proc_pronamespace, &isnull);
> schemaname = get_namespace_name(nsoid);
> ReleaseSysCache(tuple);
That would work. Since pronamespace is one of the fixed non-nullable
columns of pg_proc, you don't really need to use SysCacheGetAttr: you
can just map the C struct onto the tuple and grab the field directly.
nsoid = ((Form_pg_proc) GETSTRUCT(tuple))->pronamespace;
utils/cache/lsyscache.c contains lots of examples of this sort of thing.
(get_namespace_name is one, in fact.)
regards, tom lane
Beautiful, just what I was looking for. Thnx, John > -----Original Message----- > From: Tom Lane [mailto:tgl@sss.pgh.pa.us] > Sent: Tuesday, February 15, 2005 6:31 AM > To: Michael Fuhr > Cc: John Hansen; pgsql-hackers@postgresql.org > Subject: Re: [HACKERS] Schema name of function > > Michael Fuhr <mike@fuhr.org> writes: > > On Mon, Feb 14, 2005 at 11:11:53AM -0500, Tom Lane wrote: > >> In C, it'd be a lot easier (and faster) to do a couple of > >> SearchSysCache calls than to use SPI to get those rows. > > > The following appears to work -- does it look right, aside from the > > missing error checking? > > > tuple = SearchSysCache(PROCOID, > > ObjectIdGetDatum(fcinfo->flinfo->fn_oid), > > 0, 0, 0); > > nsoid = SysCacheGetAttr(PROCOID, tuple, > > Anum_pg_proc_pronamespace, &isnull); > > schemaname = get_namespace_name(nsoid); > > ReleaseSysCache(tuple); > > That would work. Since pronamespace is one of the fixed > non-nullable columns of pg_proc, you don't really need to use > SysCacheGetAttr: you can just map the C struct onto the tuple > and grab the field directly. > > nsoid = ((Form_pg_proc) GETSTRUCT(tuple))->pronamespace; > > utils/cache/lsyscache.c contains lots of examples of this > sort of thing. > (get_namespace_name is one, in fact.) > > regards, tom lane > >