Managing Automated Database Maintenance Tasks. Oracle Database has automated several common maintenance tasks typically performed by database administrators. These automated maintenance tasks are performed when the system load is expected to be light. You can enable and disable individual maintenance tasks, and can configure when these tasks run and what resource allocations they are allotted. In this chapter: Note. This chapter explains how to administer automated maintenance tasks using PL/SQL packages. An easier way is to use the graphical interface of Enterprise Manager. An example is a task that gathers statistics on schema objects for the query optimizer. Automated maintenance tasks run in maintenance windows, which are predefined time intervals that are intended to occur during a period of low system load. You can customize maintenance windows based on the resource usage patterns of your database, or disable certain default windows from running. You can also create your own maintenance windows. Oracle Database has three predefined automated maintenance tasks: Automatic Optimizer Statistics Collection—Collects optimizer statistics for all schema objects in the database for which there are no statistics or only stale statistics. I have an application which gets called by a scheduled task. It moved from Windows Server 2003 to Windows Server 2008. On 2003, the app ran in the directory where the. ![]() The statistics gathered by this task are used by the SQL query optimizer to improve the performance of SQL execution. Automatic Segment Advisor—Identifies segments that have space available for reclamation, and makes recommendations on how to defragment those segments. You can also run the Segment Advisor manually to obtain more up- to- the- minute recommendations or to obtain recommendations on segments that the Automatic Segment Advisor did not examine for possible space reclamation. ![]() Back in December, I recommended ways to remind yourself to do regular. A scheduling service (a.k.a. Z-Cron is a scheduler which. NOTE 1: This tutorial was created specifically for Windows 8 but it should. Special offer (until June 30, 2017) VIP Task Manager Professional is task and project management software which allows multiple users to plan, schedule, share, track. PCs are marvelous tools, aren’t they? They can do so much for us, but they’re hardly the user-friendly home computers promised in science-fiction, which can. ![]() Automatic SQL Tuning Advisor—Examines the performance of high- load SQL statements, and makes recommendations on how to tune those statements. You can configure this advisor to automatically implement SQL profile recommendations. However, the OSs' Schtasks tool. The /disable switch is only a feature of Vista/7/2008R2/2012. You can simply rename the task.job file to "disable" it. The Summary appears in the center pane, under Active Tasks. Below, you’ll see several entries dealing with third party software. Scheduled Stuff You Don’t. By default, all three automated maintenance tasks are configured to run in all maintenance windows. About Maintenance Windows A maintenance window is a contiguous time interval during which automated maintenance tasks are run. Maintenance windows are Oracle Scheduler windows that belong to the window group named MAINTENANCE. A Scheduler window can be a simple repeating interval (such as . Each job is assigned a job name that is generated at run time. All automated maintenance task job names begin with ORA$AT. For example, the job for the Automatic Segment Advisor might be called ORA$AT. When an automated maintenance task job finishes, it is deleted from the Oracle Scheduler job system. However, the job can still be found in the Scheduler job history. Note. To view job history, you must log in as the SYS user. In the case of a very long maintenance window, all automated maintenance tasks except Automatic SQL Tuning Advisor are restarted every four hours. This feature ensures that maintenance tasks are run regularly, regardless of window size. The framework of automated maintenance tasks relies on maintenance windows being defined in the database. Table 2. 6- 1 lists the maintenance windows that are automatically defined with each new Oracle Database installation. Configuring Automated Maintenance Tasks. To enable or disable specific maintenance tasks in any subset of maintenance windows, you can use the DBMS. You do so by calling the DISABLE procedure of the DBMS. For example, you can completely disable the Automatic SQL Tuning Advisor task as follows. You can disable a maintenance task for a specific window. The following example disables the Automatic SQL Tuning Advisor from running in the window MONDAY. You can customize maintenance windows using the DBMS. For example, the following script changes the duration of the maintenance window SATURDAY. If you change a window when it is currently open, the change does not take effect until the next time the window opens. Creating a New Maintenance Window. To create a new maintenance window, you must create an Oracle Scheduler window object and then add it to the window group MAINTENANCE. You use the DBMS. This window runs for one hour daily between 5 a. The window continues to exist but no longer runs automated maintenance tasks. Any other Oracle Scheduler jobs assigned to this window continue to run as usual. The following example removes EARLY. Automated maintenance tasks run under its subplan ORA$AUTOTASK. This subplan divides its portion of total resource allocation equally among the maintenance tasks. DEFAULT. Of that allocation, 2. The maximum utilization limit for ORA$AUTOTASK. Therefore, even if the CPU is idle, this group/plan cannot be allocated more than 9. CPU resources. To reduce or increase resource allocation to the automated maintenance tasks, you make adjustments to DEFAULT. Note also that the Database Resource Manager does not begin to limit resource allocations according to resource plans until 1. CPU is being used. Note. Although DEFAULT. If you do change a maintenance window resource plan, ensure that you include the subplan ORA$AUTOTASK. For information on changing resource allocations, see Chapter 2. The weekend maintenance windows, SATURDAY. The window group MAINTENANCE. The list of predefined maintenance windows is given in Table 2. Table 2. 6- 1 Predefined Maintenance Windows. Window Name. Description. MONDAY. It provides information about some objects targeted by those jobs, as well as some additional statistics from previous instantiations of the same task. Some of this additional data is taken from generic Scheduler views. DBA. Jobs are added to this view after they finish executing. DBA. Primarily used by Enterprise Manager. DBA. This information is viewable in the Job History page of Enterprise Manager.
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