How to delete outdated data regularly in Oracle database

In Oracle database, data is a very precious resource, and they will be stored in different tables and databases. Over time, data accumulates and takes up a lot of storage space. On the other hand, the data in some tables may be outdated or no longer needed. The storage space occupied by this data can be released and no longer needs to be accessed when querying, thereby improving database performance. Therefore, it is very necessary to regularly delete obsolete or no longer needed data in the Oracle database.

The following describes how to use scheduled tasks in Oracle database to delete outdated data.

1. Understand scheduled tasks

Scheduled tasks are a commonly used automated management tool in Oracle databases. Through scheduled tasks, you can set SQL statements to be executed at specific points in time to complete database management tasks. Oracle database provides a variety of scheduled task types, such as time-based, event-based, and message-based tasks. These tasks can be managed through Oracle's Enterprise Manager or the command line interface.

2. Creating a scheduled task

Creating a scheduled task using Oracle Enterprise Manager is very simple. Just follow these steps:

1. Click on the "Jobs" option in the "Database" tab.
2. Click the "Create" button to create a new task.
3. Enter the task name, description and other basic information.
4. Select the task type. In this example, SQL*Plus Script is selected, but you could also select a PL/SQL package or stored procedure.
5. Enter the SQL statement to complete the required operation. In this example, use the following SQL statement to delete records older than 90 days in the log table:

delete from log_table where log_date < sysdate - 90;

6. Set the execution frequency and time of the task. For example, you can set a task to run every morning at 2 o'clock.
7. Save the task and view its status.
8. Manage scheduled tasks

Once a task is created, it can be managed using Oracle Enterprise Manager or the command line interface. Scheduled tasks can be modified, disabled or deleted at any time. You can also use Oracle's monitoring tools to check task execution and success rates. If the task execution fails, you can view logs and error information to help diagnose the problem.

Summary

It is very necessary to regularly delete obsolete or no longer needed data in the Oracle database. Using a scheduled task, you can easily complete this task and execute it automatically at a predetermined time point. By setting the appropriate execution frequency and timing, you can save time and resources and improve database performance.

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