1z0-054 | The Secret of Oracle 1z0-054 examcollection
Q11. During a proactive database performance monitoring routine, on examining the AWR report you find that log file sync appears among the top 5 wait events.
What does this event indicate?
A. Frequent logfile switches are occurring.
B. Redo is generated faster than LGWR can write it out.
C. Frequent commits or rollbacks are taking place in the application.
D. Frequent incremental checkpoints are taking place in the database.
Answer: C
Q12. View the Exhibit and examine the content.
ALLOCATED_SPACE and FREE_SPACE indicate that a large amount of space is allocated to the temporary tablespace that is being used.
Which action would reclaim the space and refresh these values?
Exhibit:
A. shrinking the tablespace
B. closing all the current sessions
C. restarting the database instance
D. forcing a checkpoint or waiting for a checkpoint to occur
Answer: A
Q13. Identify the reason why chained or migrated rows in a table cause performance degradation when you access them.
A. because the ROWID changes for these rows
B. because these rows make existing indexes invalid
C. because it is not possible to use indexes to retrieve these rows
D. because retrieving these rows requires more than one data block to be accessed
E. because the rows force queries to use temporary segments while retrieving them
Answer: D
Q14. View the Exhibit and examine the content. ALLOCATED_SPACE and FREE_SPACE are not matching with the TABLESPACE_SIZE value.
What would you conclude from this?
Exhibit:
A. A new temporary file is added to the tablespace.
B. The temporary space was not sufficient for sort operations.
C. The temporary space allocated to large sort operations is not deallocated.
D. TEMP_L is a default temporary tablespace because the numbers show some overhead on this tablespace.
Answer: C
Q15. In which case is the database buffer cache NOT used?
A. when physical I/Os are performed to read from data files
B. when the database writer process writes to the SYSTEM tablespace
C. when the server process writes sort data to the temporary tablespace
D. when the database writer process writes undo data to the undo tablespace
Answer: C
Q16. The Automatic Workload Repository (AWR) snapshot interval is set to 1 hour. A user of your database notifies you that the system was slow between 10:00 PM and 10:10 PM, but the Automatic Database Diagnostic Management (ADDM) analysis for the time period between 10:00 PM and 11:00 PM does not show this performance problem.
What would you suggest to analyze this performance problem for the user?
A. SQL Tuning Advisor
B. SQL Performance Analyzer
C. Active Session History report
D. AWR Compare Periods report
Answer: C
Q17. View the Exhibit and analyze the content of V$BUFFER_POOL_STATISTICS.
Why does the query on the EMP table not access buffers from the keep pool?
Exhibit:
A. because the query used SCOTT.EMP instead of EMP
B. because the query with * always uses the default pool
C. because the query with * always forces physical I/Os that bypass the keep pool
D. because the blocks of the EMP table are already available in one of the other buffer pools
Answer: D
Q18. Which three factors influence the optimizer's behavior while choosing an optimization approach and goal for a SQL statement? (Choose three.)
A. parsing of a SQL statement
B. operating system (OS) statistics
C. object statistics in the data dictionary
D. the OPTIMIZER_MODE initialization parameter
E. optimizer SQL hints for changing the query optimizer goal
Answer: CDE
Q19. Examine the following block that executes a SQL Performance Analyzer task:
begin
dbms_sqlpa.execute_analysis_task(task_name => 'SPA_SKD4', execution_type => 'TEST EXECUTE', execution_name => 'before');
end;
Which two statements are true about the execution? (Choose two.)
A. It generates execution plans and execution statistics.
B. It executes only the query part of the DML statements.
C. The test plans are generated and added to plan baseline.
D. The test plans are executed, but not generated if they are available in the plan baseline.
Answer: AB
Q20. Which two statements are true about the database buffer cache? (Choose two.)
A. A buffer can be written to by many processes at the same time.
B. A buffer containing a block that is identical to the block on disk is called free buffer.
C. A buffer containing a block that is being accessed by a process is called dirty buffer.
D. A buffer available to be overwritten with a different database block at any time is called a dirty buffer.
E. A buffer can contain a different version of a block that is available in a different buffer of the same cache.
Answer: BE