Oracle Database 11 g - Online Public Access Catalog

220 CHAPTER 4 ■ PERFORMANCE MANAGEMENTNote that you can use the expiration attribute to set the time (in days) for which Oraclemust maintain a baseline. The default value is null, meaning the database will never drop abaseline.Generating a Template for a Repeating BaselineYou can specify a template for creating a repeating baseline using the following procedure:dbms_workload_repository.create_baseline_template(day_of_week IN VARCHAR2,hour_in_day IN NUMBER,duration IN NUMBER,start_time IN DATE,end_time IN DATE,baseline_name_prefix IN VARCHAR2,template_name IN VARCHAR2,expiration IN NUMBER,dbid IN NUMBER DEFAULT NULL);You can use the drop_baseline_template procedure to drop either a one-time or a repeatingbaseline template.Ability to Rename BaselinesYou can use the new rename_baseline procedure to rename an AWR baseline, as shown in thefollowing example:SQL> execute dbms_workload_repository.rename_baseline –(old_baseline_name =>'old_baseline', -new_baseline_name => 'new_baseline', dbid=3863017760);The dbid parameter, as in the earlier example, is optional, and the database identifier forthe local database will be used as the default value for dbid if you don’t provide one.Ability to Set Expiration Dates for BaselinesWhen you use the create_baseline procedure to create a new AWR baseline, you can specifythe expiration time for that baseline by setting a value for the new expiration attribute of theprocedure. The default value of null for the expiration attribute means that a baseline willnever expire, which was the only behavior possible in Oracle Database 10g.Baselines and Template Dictionary ViewsThere are several new DBA views to help you manage AWR baselines and templates. The threeviews that will help you the most are as follows:• DBA_HIST_BASELINE (modified)• DBA_HIST_BASELINE_TEMPLATE (new)• DBA_HIST_BASELINE_DETAILS (new)