Initially, for the Automatic Workload Repository (AWR) statistics, the retention period is set to 7
days, the collection interval is set to 30 minutes and the collection level is set to Typical in your
production database. You have been using the Memory Advisor for the last three months to
generate recommendations for tuning memory components. However, when you observe the
Memory Advisor on a Friday, you find that the statistics are available only for two days, Thursday
and Friday, of that week. What would have caused the statistics to be removed?
A.
On Wednesday, the statistics have been purged.
B.
On Wednesday, the retention period has been set to zero.
C.
On Wednesday, the collection interval has been set to zero.
D.
On Wednesday, the collection level has been changed to All.
E.
On Wednesday, the retention period has been set to one day.
F.
On Wednesday, the retention period has been set to two days.
G.
On Wednesday, the collection level has been changed to Typical.
H.
On Wednesday, the collection interval has been set to 1440 minutes.
Advisors are powerful tools for database management. They provide specific advice on how to address key database management challenges, covering a wide range of areas including space, performance, and undo management. In general, advisors produce more comprehensive recommendations than alerts. This is because alert generation is intended to be low cost and have minimal impact on performance, whereas advisors consume more resources and perform more detailed analysis. This, along with the what-if capability of some advisors, provides vital information for tuning that cannot be procured from any other source. You run advisors from Oracle Enterprise Manager Database Control (Database Control). Some are also run automatically during maintenance windows (time periods).
Advisors are provided to help you improve database performance. These advisors include Automatic Database Diagnostic Monitor (ADDM), SQL advisors, and memory advisors. For example, the Shared Pool Advisor, graphically displays the impact on performance of changing the size of this component of the System Global Area (SGA).
You can run a performance advisor when faced with the following situations:
You want to resolve a problem in a specific area, for example, to determine why a given SQL statement is consuming 50 percent of CPU time and what to do to reduce its resource consumption.You can use the SQL Tuning Advisor.
During application development, you want to tune a new schema and its associated SQL workload for optimal performance. You can use the SQL Access Advisor.
You are planning to add memory to your system. You can use the Memory Advisor to determine the database performance impact of increasing your SGA or PGA (Program Global Area).
You can run all advisors from the Advisor Central home page, accessible through a link on the Database Home page. You can also invoke many of the advisors from the Performance page, through recommendations from ADDM, or from alerts.
available only for two days, so the retention period has been set to two days.