452  Chapter 10  n  Diagnosing the Database and Managing Performance

Answers to Review Questions

1.A, C, D.  FOREGROUND_DUMP_DEST is not a valid initialization parameter, so option B is incorrect. DIAGNOSTIC_DEST is the new parameter that replaces the parameters in options A, C, and D, so E is incorrect.

2.​B.  When $ORACLE_BASE is set, it is the default value for DIAGNOSTIC_DEST.

3.​C.  Option A is incorrect because the correct order is diag/rdbms. Option B is incorrect because the correct order is <dbname>/<instname>.

4.​A, E.  Options B, C, and D are each fundamental tasks of the Support Workbench problemresolution process.

5.​B.  Option A is incorrect because IPS does not delete files not associated with a package that will be sent to Oracle Support. Option C is incorrect because IPS does not open an Oracle service request for each critical error. D is incorrect because IPS does not display critical errors on the database home page.

6.​D.  All other sequences are incorrect. D is the correct sequence. First create the new package, then view the package contents. Next view the manifest, then schedule the job to upload the data for the incident to Oracle Support.

7.​B.  Option A is incorrect because reduced MTTR is an advantage of BMR. Option C is incorrect because the datafiles remaining online is an advantage of BMR. Since A and C are advantages, D is also incorrect. Option B is the correct choice because it is not an advantage of BMR.

8.​E.  Option A is correct because if you attempt to analyze a table or index that has a corrupt block, the ANALYZE command will indicate it. Option B is correct because the dbv command (DBVERIFY utility) is used to verify the data-structure integrity of an offline datafile. DBVERIFY will let you know if the datafile fails the integrity check. Option C is correct unless you have used DBMS_REPAIR.SKIP_CORRUPT_BLOCKS to permit queries to skip corrupt blocks. D is correct because the RMAN BACKUP command will detect corruption by default.

9.​A, C.  Option B is incorrect because logical corruptions are not repairable by BMR. Option D is incorrect because you must use a level 0 or full backup for the restore. Option E is incorrect because ARCHIVELOG mode is a requirement for BMR.

10.​B, C.  Option A is incorrect because the syntax is wrong. Option D is incorrect because BLOCK doesn’t belong. B is how we recover all corrupt blocks listed in V$DATABASE_BLOCK_ CORRUPTION. C is the correct syntax to recover just the one block that we’ve identified as corrupt.

11.​D.  Option A is incorrect because there is no direct link on the Software and Support home page to the SQL Advisors. You use either sequence B or C to get to the SQL Advisors and to the Automatic SQL Tuning Advisor page; from there, you can see the results of the most recent Automatic SQL Tuning Advisor task.

12.​D.  Options A, B, and C are not valid choices when creating a SQL tuning set. During the filter options step, the DBA can choose the SQL attributes, the operator, and the values to use as filter conditions.

13.​A.  Option B is incorrect because there is no Manual Tuning Task Results option. C is incorrect because there is no Manual SQL Tuning Advisors option.

14.A.  Option B is incorrect because the manual SQL Tuning Advisor task does not tune the SQL statements. C is incorrect for the same reason.

15.E.  All of the options are correct. The SQL Access Advisor recommends indexing, partitioning, and materialized view changes to improve performance.

16.B.  Option A is incorrect because SQL Access Advisor recommendations are not automatically implemented. Option C is incorrect because the DBA can choose which recommendations to schedule and implement from the task result set. D is incorrect because the recommendations are not automatically scheduled for implementation.

17.C.  The correct sequence is capture, preprocess, replay, analyze.

18.B, C.  Option A is incorrect because the data divergence between the capture and replay databases should be minimized. Option D is incorrect because the database should be started in RESTRICTED mode, and then the workload capture process will switch the database to UNRESTRICTED. Option E is incorrect because you can define either inclusion or exclusion filters for a workload capture, but not both.

19.E.  Option A is incorrect because workload capture is for the database, not for individual instances. B is incorrect because the correct procedure is to shut down all instances before you begin workload capture. Option C is incorrect; after the shutdown of all instances, start one instance to begin workload capture, and then start the remaining instances after capture begins. Workload capture and replay are supported in RAC, so D is incorrect.

20.D.  Option A is incorrect; DML and SQL results drive data divergence. Option B is incorrect because error divergence, not performance divergence, happens when errors that occur in the capture system don’t occur in the replay system. Top SQL statements should behave the same in the capture and replay systems, unless there is a data-divergence issue, so C is incorrect. E is incorrect because the time of day should have no impact on differences between the capture and replay systems. It is possible that other workloads running on the capture and replay systems that have a time-of-day trend might impact performance, but that is an extraneous variable, not a cause.

In this chapter, we will discuss how to most effectively manage memory, space, and resources. For memory management, we will discuss the Oracle 11g feature Automatic

Memory Management, which enables the DBA to set one memory parameter for management of the instance memory. For space management, we will discuss resumable space allocation, transportable tablespaces and databases, and shrinking segments. For resource management, we will discuss the Database Resource Manager functionality and components.

Memory management is critical to database instance performance and has often been a source of frustration for Oracle DBAs. With Oracle 11g, much of the manual memory management has been replaced with automatic memory options—either to automatically manage all of the instance memory or to automatically manage the SGA and PGA as two separate pools.

We’ll cover two features (resumable space allocation and shrinking segments) for managing the efficient utilization of space resources and two features (transportable tablespaces and transportable databases) for managing large-scale data movement. The resumable space allocation feature allows you to efficiently utilize space resources and prevent transaction aborts when space limitations are encountered. Shrinking segments allow you to eliminate white space in a segment in place while the segment remains online and available for application use. For large-scale movement of tablespaces from one database to another, the DBA can use the transportable tablespaces feature. To move an entire database, even to another platform, you can use the transportable database feature.

The Database Resource Manager is a robust and mature feature that allows the DBA to manage scarce session, I/O, and CPU resources within an Oracle instance. The Database Resource Manager allows you to create groups, policies, and plans to control the utilization of system resources.

Throughout this chapter, we will show command-line and Oracle Enterprise Manager methods for managing memory, space, and resources.

Exam objectives are subject to change at any time without prior notice and at Oracle’s sole discretion. Please visit Oracle’s Training and Certification website (http://www.oracle.com/education/certification/) for the most current exam-objectives listing.