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Friday 2 December 2011

Informatica and Stored Procedures

A. Described below is a scenario where the requirement is to have a stored procedure that returns a cursor as a source. PowerCenter does not support a stored procedure that returns a cursor as a source. The workaround for this is
1. The procedure that will load the data to a new table:
CREATE OR REPLACE procedure load (p_initial_date in date, p_final_Date in date) as
str_load varchar2 (500);
str_clean varchar2 (500);
begin
str_clean:= ‘DELETE FROM EMP’;
str_load:= ‘INSERT INTO EMP select * from EMPLOYEE where DOJ between trunc
(p_initial_date) and trunc (p_final_Date) ‘;
execute immediate str_clean;
execute immediate str_load;
EXCEPTION
WHEN OTHERS
THEN
ROLLBACK;
end load;

2. Create the table that will receive the data from the procedure:
SQL> create table EMP as SELECT * from EMPLOYEE where 1 > 2;
3. Add a Store Procedure transformation to the PowerCenter mapping. This transformation will execute this new procedure called as LOAD on this example.
4. Set the run method to be Source Pre Load, to be executed before read the source table.
5. Import the EMP table as a Source Definition. This table will be populated by the new Store Procedure.
A. If the original store procedure is used by the customer application and you can’t change the source code, you can create a new store procedure that call the original one (without inserting into a table), and execute the insert on the new table executing a loop on the returned cursor.
B. Given below is a situation where you wanted to pass a mapping variable to a stored procedure transformation (it can either be connected or unconnected).
Connected Stored Procedure
The parameters that are passed to a connected Stored Procedure have to be linked from another transformation.
Given below are the steps to pass mapping variable to a connected Stored Procedure transformation:
  1. Create an Expression transformation.
  2. Create an output port in the Expression transformation with the following expression:
$$mapping_variable
This sets the value of this output port to the mapping variable.
  1. Link this output port to the Stored Procedure transformation.
Unconnected Stored Procedure
For unconnected Stored Procedure transformations you can use the mapping variable in the expression calling the stored procedure.
Follow the steps below to pass mapping variable to a unconnected Stored Procedure transformation:
  1. Create an Expression transformation.
  2. Create an output port in the Expression transformation with the following expression:
: SP.GET_NAME_FROM_ID ($$mapping_variable, PROC_RESULT)

In case if you are attempting to use a mapping variable to store the output value of the stored procedure, the session will fail with the below error. “TE_7002 Transformation Parse Fatal Error; transformation stopped: invalid function reference. Failed to Initialize Server Transformation.”

To resolve the issue replace the mapping variable with the PROC_RESULT system variable.
Example:
--Incorrect, using a mapping variable:
:SP.PROCEDURE(FIELD1, $$mapping_variable)
Correct, using the PROC_RESULT system variable:
:SP.PROCEDURE(FIELD1,PROC_RESULT)
Or
:SP.PROCEDURE($$mapping_variable,PROC_RESULT)
The PROC_RESULT system variable assigns the stored procedure output to the port with this expression.
You are welcome to share your thoughts/suggestions to inflate any “Infa Tip” -