Configuring DLL in oracle environment

Question

Hello,
I'm using Windows and my Oracle DB version is 9.2.0.1. I want to use DLL (proc & fun) in my pl/sql procedures.
What are the steps to configure the DLL in Oracle. Is it same as configuring External procedures?
Do we need to configure both listener.ora and tnsnames.ora files for this purpose?
Cheers
Ram

Answer 1

You must build an external library, declare it as a LIBRARY object inside Oracle, configure your lib paths, and configure your listener.
Once you've met the config procedures, next you have to create a wrap function to access your external funcion inside a PLSQL block.
Check this documents:
http://download-west.oracle.com/docs/cd/B19306_01/appdev.102/b14289/dcimethcj.htm#sthref250
http://download-west.oracle.com/docs/cd/B19306_01/server.102/b15658/ldr_demo.htm#sthref565
http://download-west.oracle.com/docs/cd/B19306_01/server.102/b14231/manproc.htm#ADMIN00501
Step 1 - Make entry in the TNSNAMES.ORA.
======
Make the following entry in the TNSNAMES.ORA:
extproc_connection_data.world =
     (DESCRIPTION =
          (ADDRESS =
          (PROTOCOL = IPC)
          (KEY = extproc))
          (CONNECT_DATA =
               (SID = extproc)
Step 2 - Make the necessary entries in the LISTENER.ORA.
======
You can either add an entry to the existing listener or add another listener
process.
Option 1: Add an Entry to the Existing Listener
The information contained in each listener differs. Defining the
listener process is done in two parts. The first part is as follows:
LISTENER =
(ADDRESS_LIST =
(ADDRESS=
(PROTOCOL= IPC)
(KEY= V803)
(ADDRESS=          <-Add this line.
(PROTOCOL= IPC) <-Add this line.
(KEY= extproc)     <-Add this line.
(ADDRESS=
(PROTOCOL= TCP)
     (Host= ###.#.#.#)
(Port= ####)
Step 3 - Start the listener process.
======
Any modifications to the existing listener require that you stop and
restart the listener to reload the new listener configuration. Adding a
second listener process, instead of modifying the current, only requires
the startup of the new listener process.
Step 4 - Create a sample DLL using the following code.
======
The following is a basic example of an external procedure. It is a good
way to test to ensure that the environment (mainly the listener) is configured
correctly.
Note: For the remaining steps, the DLL name should be MYEXTPROC.DLL.
#include <stdio.h>
int __declspec(dllexport) square(int x)
return(x*x);
Step 5 - Move the DLL to same server where the database is located.
======
The DLL can be placed in any directory. One approach would be to create an
EXTPROC directory under the ORACLE_HOME and use this to house all external
procedures.
Step 6 - Create the required library.
=======
Log into SQL*Plus and create a library to be associated with the external
procedure.
Note: The user must have CREATE LIBRARY privileges.
CREATE LIBRARY <mylib> AS <path\filename>;
SQL> CREATE LIBRARY SQUARE_LIB AS 'D:\ORANT\EXTPROC\MYEXTPROC.DLL';
Step 7 - Register the external procedure.
======
An external procedure is not called directly. Instead, you call the PL/SQL
subprogram that registers the external procedure. This can either be a
Function or a Stored Procedure.
CREATE OR REPLACE FUNCTION <FunctionName> (<parm1>...) RETURN <value> AS
EXTERNAL LIBRARY <mylib>
NAME "<Name Of Function In DLL>"
LANGUAGE C;
CREATE OR REPLACE PROCEDURE <ProcedureName> (<parm1>...) AS
EXTERNAL LIBRARY <mylib>
NAME "<Name Of Function In DLL>"
LANGUAGE C;
CREATE OR REPLACE FUNCTION square_of (X BINARY_INTEGER)
RETURN BINARY_INTEGER AS
EXTERNAL LIBRARY SQUARE_LIB
NAME "square"
LANGUAGE C;
Step 8 - Run the external procedure.
======
Use the following code to execute the external procedure:
CREATE OR REPLACE PROCEDURE EXTPROCTEST (X BINARY_INTEGER) AS
RetValue BINARY_INTEGER;
BEGIN
RetValue := square_of(X);
DBMS_OUTPUT.PUT_LINE(RetValue);
End;
EXECUTE EXTPROCTEST(15);