ORA-00942 error in simple stored proc

Question

Guys,
I'm trying to learn to write some procedures in oracle and have started with the following;
CREATE OR REPLACE PROCEDURE sp__who
IS
BEGIN
FOR rec IN (SELECT s.SID, s.serial#, p.spid, s.osuser, s.program,
s.status
FROM v$process p, v$session s
WHERE p.addr = s.paddr)
LOOP
DBMS_OUTPUT.put_line ('SID: ' || rec.SID);
DBMS_OUTPUT.put_line ('Serial Nbr: ' || rec.serial);
DBMS_OUTPUT.put_line ('SPID: ' || rec.spid);
DBMS_OUTPUT.put_line ('OS User: ' || rec.osuser);
DBMS_OUTPUT.put_line ('Program: ' || rec.program);
DBMS_OUTPUT.put_line ('Status: ' || rec.status);
DBMS_OUTPUT.put_line ('------------------------------');
END LOOP;
END sp__who;
SHOW ERRORS;
This is failing with a PL/SQL: ORA-00942: table or view does not exist - it seems to be complaining about v$session and v$process - I do have access to these as I can run the select by itself fine...
Any ideas why?
Also, can anyone suggest a good website for learning PL/SQL and oracle procedure writing?
Cheers!
Pete

Answer 1

I'm a DBA (Sybase / SQL Server DBA!) and I'm learning to support oracle instances in my current role.
The stored procedure will be used to extract a list of users active or otherwise in the database... Ideally giving enough information to make decisions easier when it comes to killing processes, etc. Replicating in part, the sybase equivalent stored procedures. (long term plan will be to recreate all the sybase sp_ procedures in oracle)
What's written so far is obviously very basic and will need further enhancements to make it useful as intended - but having zero experience of writing procs in Oracle I thought it best to start with a simple select :-)