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Oracle OCP 1Z0-050（29题）解析

QUESTION 29:

You plan to collect the Automatic Workload Repository (AWR) data every Monday morning for a month. You want Oracle Database to automatically create a baseline every Monday and remove the old baseline. What is the correct action to achieve this?

A. Create and populate a SQL Tuning Set from the AWR on every Monday.

B. Change the RETENTION setting for the AWR snapshots to 7 days on Monday.

C. Create a repeating baseline template.

D. Insert a finding directive for future ADDM tasks.

Answer: C

解析：

参考Oracle官方文档

5.3.3.2 Creating a Repeating Baseline Template

This section describes how to create a repeating baseline template. A repeating baseline template can be used to automatically create baselines that repeat during a particular time interval over a specific period in the future. For example, you can create a repeating baseline template869 to generate a baseline that repeats every Monday from 5:00 p.m. to 8:00 p.m. for the year 2009.

To create a repeating baseline template, use the CREATE_BASELINE_TEMPLATE procedure:

BEGIN    DBMS_WORKLOAD_REPOSITORY.CREATE_BASELINE_TEMPLATE (                   day_of_week => 'monday', hour_in_day => 17,                   duration => 3, expiration => 30,                   start_time => '2009-04-02 17:00:00 PST',                   end_time => '2009-12-31 20:00:00 PST',                   baseline_name_prefix => 'baseline_2009_mondays_',                   template_name => 'template_2009_mondays',                   dbid => 3310949047);END;/

The day_of_week parameter specifies the day of the week on which the baseline will repeat. The hour_in_day parameter specifies the hour in the day when the baseline will start. The duration parameter specifies the duration, in number of hours, that the baseline will last. The expiration parameter specifies the number of days to retain each created baseline. If set to NULL, then the baselines never expires. The start_time parameter specifies the start time for the baseline to be created. The end_time parameter specifies the end time for the baseline to be created. The baseline_name_prefix parameter specifies the name of the baseline prefix that will be appended to the data information when the baseline is created. The template_name parameter specifies the name of the baseline template. The optional dbid parameter specifies the database identifier. If unspecified, then the local database identifier is used as the default value.

In this example, a baseline template named template_2009_mondays is created that will generate a baseline on every Monday from 5:00 p.m. to 8:00 p.m. beginning on April 2, 2009 at 5:00 p.m. and ending on December 31, 2009 at 8:00 p.m. on the database with a database ID of 3310949047. Each of the baselines will be created with a baseline name with the prefix baseline_2009_mondays_ and will expire after 30 days.

5.3.3.3 Dropping a Baseline Template

This section describes how to drop an existing baseline template. Periodically, you may want to remove baselines templates that are no longer used to conserve disk space.

To drop a baseline template:

Review the existing baselines in the DBA_HIST_BASELINE_TEMPLATE view to determine the baseline template you want to drop.

Use the DROP_BASELINE_TEMPLATE procedure to drop the desired baseline template:

BEGIN  DBMS_WORKLOAD_REPOSITORY.DROP_BASELINE_TEMPLATE (                   template_name => 'template_2009_mondays',                   dbid => 3310949047);END;/

The template_name parameter specifies the name of the baseline template that will be dropped. In the example, the name of baseline template that will be dropped is template_2009_mondays. The optional dbid parameter

 specifies the database identifier, which in this example is 3310949047. If you do not specify a value for dbid, then the local database identifier is used as the default value.

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