Oracle’s DBMS_JOB.REMOVE procedure is a part of the Oracle Database Job Scheduler, which allows for the scheduling of jobs units of work that can be scheduled to run one or more times. The DBMS_JOB package, in particular, has been traditionally used in Oracle databases to manage jobs before the more advanced DBMS_SCHEDULER was introduced in Oracle 10g. Despite the introduction of DBMS_SCHEDULER, DBMS_JOB continues to be supported for backward compatibility and its simplicity in scheduling and managing jobs in the database.
Purpose of DBMS_JOB.REMOVE
The DBMS_JOB.REMOVE procedure is specifically designed to remove a job from the job queue. Once a job is removed, it is permanently deleted from the database and cannot be restored. This is particularly useful for cleaning up obsolete, completed, or no longer required jobs to maintain the efficiency of the job queue and the overall database performance.
Syntax
The basic syntax of the DBMS_JOB.REMOVE procedure is straightforward:
DBMS_JOB.REMOVE(job IN BINARY_INTEGER);
job: This parameter is the identifier (job number) of the job you wish to remove from the job queue. This identifier is assigned by the database when the job is submitted.
Usage Example
Before you can remove a job, you need to know its job number. You can find this number by querying the USER_JOBS or DBA_JOBS view depending on your access level. Here’s a simple example that demonstrates how to remove a job:
DECLARE job_number BINARY_INTEGER; BEGIN -- Assuming 42 is the job number for the job you want to remove job_number := 42; DBMS_JOB.REMOVE(job => job_number); COMMIT; END; /
It’s important to commit the transaction to ensure that the removal of the job is persisted in the database.
Considerations
Commit Required: After calling DBMS_JOB.REMOVE, a commit is required to make the removal permanent.
Permissions: The user executing DBMS_JOB.REMOVE needs to have the necessary privileges to manage jobs, typically requiring either the DBA role or specific execute privileges on the DBMS_JOB package.
Migration to DBMS_SCHEDULER: Oracle recommends migrating jobs to DBMS_SCHEDULER for more advanced features, flexibility, and improved performance. DBMS_SCHEDULER offers a more robust framework for job scheduling, including support for lightweight jobs, chains, file watchers, and remote database jobs.
In summary, DBMS_JOB.REMOVE is a useful procedure for managing the lifecycle of jobs within an Oracle database, ensuring that the job queue remains relevant and optimized. However, for more complex scheduling needs, exploring the capabilities of DBMS_SCHEDULER is advisable.