Oracle PL/SQL Programming: A Developer's Workbook

Chapter 25. DBMS_JOB Built-in Package

The DBMS_JOB package allows you to schedule PL/SQL routines, or jobs, to run periodically based on intervals you define. Each job has an associated job ID, a next execution date, an interval function that computes the next execution date, and a flag indicating whether the job is broken. This chapter tests your ability to use the DBMS_JOB package to submit new jobs to the job queue, change a job’s execution parameters (for instance, how often it runs), and remove a job from the queue.

Beginner

25-1.	Why do you need the DBMS_JOB built-in package?
25-2.	Which three INIT.ORA parameters do you (or your DBA) need to set before using the DBMS_JOB package?
25-3.	What happens when JOB_QUEUE_PROCESSES = 1, and you submit two long-running jobs that execute at the same time?
25-4.	Is it possible to execute two instance of the same job by two different SNP background processes in parallel mode?
25-5.	What are the two DBMS_JOB procedures that submit jobs? What are their parameters?
25-6.	What is the difference between the DBMS_JOB.SUBMIT and DBMS_JOB.ISUBMIT procedures?
25-7.	You submit this job, but it doesn’t execute immediately. Why? SQL> EXEC (33, 'calc_totals;', SYSDATE, 'SYSDATE + 1'); DBMS_JOB.ISUBMIT PL/SQL procedure successfully completed.
25-8.	Why does the following job never execute? DBMS_JOB.ISUBMIT ( job => 33, what => 'NULL;', next_date => NULL, interval => 'SYSDATE + 1' );
25-9.	What is wrong with this call to ISUBMIT? DBMS_JOB.ISUBMIT ( job => 33, what => 'foo', ...