savepoint&rollback

A simple rollback or commit erases all savepoints. When you roll back to a savepoint, any savepoints marked after that savepoint are erased. The savepoint to which you roll back remains.

You can reuse savepoint names within a transaction. The savepoint moves from its old position to the current point in the transaction.

If you mark a savepoint within a recursive subprogram, new instances of the SAVEPOINT statement are executed at each level in the recursive descent. You can only roll back to the most recently marked savepoint.

An implicit savepoint is marked before executing an INSERT, UPDATE, or DELETE statement. If the statement fails, a rollback to the implicit savepoint is done. Normally, just the failed SQL statement is rolled back, not the whole transaction; if the statement raises an unhandled exception, the host environment (such as SQL*Plus) determines what is rolled back.

CREATE TABLE emp_name AS SELECT employee_id, last_name, salary FROM employees;
CREATE UNIQUE INDEX empname_ix ON emp_name (employee_id);

DECLARE
   emp_id        employees.employee_id%TYPE;
   emp_lastname  employees.last_name%TYPE;
   emp_salary    employees.salary%TYPE;
BEGIN
   SELECT employee_id, last_name, salary INTO emp_id, emp_lastname,
     emp_salary FROM employees WHERE employee_id = 120;
   UPDATE emp_name SET salary = salary * 1.1 WHERE employee_id = emp_id;
   DELETE FROM emp_name WHERE employee_id = 130;
   SAVEPOINT do_insert;
   INSERT INTO emp_name VALUES (emp_id, emp_lastname, emp_salary);
EXCEPTION
   WHEN DUP_VAL_ON_INDEX THEN
      ROLLBACK TO do_insert;
      DBMS_OUTPUT.PUT_LINE('Insert has been rolled back');
END;
/

declare   
e_b exception;  
begin  
  insert into nbz_run_log (LOG_ID, LOG_TIME) values (552071, sysdate);  
  savepoint my_save;  
  insert into nbz_run_log (LOG_ID, LOG_TIME) values (552073, sysdate);  
  raise e_b;  
  commit;  
exception  
  when e_b then   
     rollback to my_save;  
     commit;    
     when others then  
     rollback;  
end;