How can I check a Remote Database is alive in a Stored Procedure

Question

Hi
In a PL/SQL stored procedure, I do a select from a table on a remote database via the database link. There is a Loop around the select as it waits for a flag to be set on the remote table. However, on several occasions, while looping, the remote database has gone down and the procedure then fails with error:
'Details ORA-02068: following severe error from ORA-02068: following severe error from 'Remote Database ' ORA-01033: ORACLE initialization or shutdown in progress ORA-06512: at "Current Database.Stored Procedure", line'
Is it possible to trap this error and prevent the procedure from crashing?
My current code is like:-
LOOP     
SELECT flag
INTO v_flag
FROM remote_table@remote_db;
     IF v_flag= 'OK'
     THEN
< Run Oracle Warehouse Builder Process Flow >
     EXIT;
     ELSE dbms_lock.sleep(600);
     END IF;
END LOOP;
Any help with this would be appreciated.
Thanks
GB

Answer 1

Hi Bernd
Thanks for your help. If I do this, I think the procedure would continue onto the 'IF' statement. I am looking for a way of looping round and trying to run the select again before moving on.
If I did something like
LOOP --- Loop 1 ---
LOOP --- Loop 2---
BEGIN
SELECT flag
INTO v_flag
FROM remote_table@remote_db;
EXCEPTION WHEN OTHERS THEN NULL;
END;
-- Need to exit if no exception ---
END LOOP;
IF v_flag= 'OK'
THEN
< Run Oracle Warehouse Builder Process Flow >
EXIT;
ELSE dbms_lock.sleep(600);
END IF;
END LOOP;
Is there a way of going back to the start of Loop 2 if there was an exception, otherwise EXIT and continue onto the 'IF' statement.