Re: getting oid of function - Mailing list pgsql-hackers

thank you for the detailed reply
But what i wanted to know is that how can we actually get a function's
oid from its
name from within postgresql code itself

Actually i ve introduced a new statement in plpgsql, that supports calling
a plpgsql function from within a plpgsql function for example

CALL function_name( <params>);

Here i only have the function name, i need to fetch the Oid of the
function so that
i can construct FmgrInfo and FunctionCallInfoData structures, so that
i can compile (if required) and execute that function.

There is a function like SearchSysCache(PROCOID,.....................
that would retrieve the pg_proc Tuple on the basis of function Oid
passed to it, so can use this function to return a pg_proc Tuple on
the basis of a function name?
Or is there any alternate function avaible that can achieve this

Thank you

regards
Sibtay

In case i am taking a wrong approach I would be thankful if anyone can
correct me.

On Mon, 14 Feb 2005 01:14:07 -0700, Michael Fuhr <mike@fuhr.org> wrote:
> On Mon, Feb 14, 2005 at 12:47:44PM +0500, Sibtay Abbas wrote:
> >
> > Is it possible to get the oid of a function on the basis of its name?.
> 
> One way is to cast the function name to regproc (or, with arguments,
> to regprocedure) and then to oid:
> 
> SELECT 'atan'::regproc::oid;
> SELECT 'length(text)'::regprocedure::oid;
> 
> See "Object Identifier Types" in the documentation for more info:
> 
> http://www.postgresql.org/docs/8.0/static/datatype-oid.html
> 
> > The scenario which i am currently facing is that i have the function name, now
> > i want search the pg_proc system catalog on the basis of the function
> > name and retrieve its Oid.
> 
> SELECT oid FROM pg_proc WHERE proname = 'funcname';
> 
> A function can have multiple records in pg_proc if it can take
> different types and/or numbers of arguments, so you might have to
> allow for that.
> 
> > Another confusion which i am facing is that, I am not sure whether Oid
> > of a function is entered in pg_proc system catalog or not. Because i
> > am not able to identify any relevant field.
> 
> oid is a system column; tools that describe tables usually don't
> show system columns.  You can query pg_attribute to see all of a
> table's columns.
> 
> http://www.postgresql.org/docs/8.0/static/ddl-system-columns.html
> http://www.postgresql.org/docs/8.0/static/catalog-pg-attribute.html
> 
> --
> Michael Fuhr
> http://www.fuhr.org/~mfuhr/
>