Oracle 1Z0-064 Free Practice Questions 2021

NEW QUESTION 1
You are administering a database that supports an OLTP workload. RESULT_CACHE_MODE is set to the default value and a result cache is configured for the instance. Multiple sessions execute syntactically similar queries without dblinks, containing functions and expressions, on tables with no DML activity. Some users complain about poor performance of these queries.
You investigate and find that the queries are frequently performing physical I/O, even though the results fetched by the queries are similar.
Which two actions do you recommend to overcome the problem affecting these queries? (Choose two.)

• A. Set the RESULT_CAHCE_MODE parameter to FORCE for the instance.
• B. Use the result cache hint in the queries.
• C. Use bind variables for similar queries instead of literals.
• D. Set the RESULT_CACHE_REMOTE_EXPIRATION parameter to a nonzero value.
• E. Configure the KEEP pool and cache the queried tables used in the KEEP pool.

Answer: AB

NEW QUESTION 2
Which three statements are true about using Real-Time Database Operations? (Choose three.)

• A. The STATISTICS_LEVEL initialization parameter must be set to ALL to enable automatic SQL monitoring for all long-running queries.
• B. The CONTROL_MANAGEMENT_PACK_ACCESS initialization parameter must be set to DIAGNOSTIC+TUNUNG to use Real-Time Database Operations.
• C. The STATISTICS_LEVEL initialization parameter can be set to TYPICAL or ALL to enable Real-Time Database Operations.
• D. Real-Time Database Operations can be enabled only at the system level.
• E. Real-Time Database Operations can be created by using the DBMS_MONITOR or DBMS_SESSION packages.
• F. Database operation monitoring starts automatically when a database operation consumes at least five seconds of the CPU or I/O time in a single execution.

Answer: BCF

NEW QUESTION 3
Which two statements are true about Active Session History (ASH)? (Choose two.)

• A. The Data Sample size available in an ASH report is dynamic and, at any given moment, is directly related to the amount of work being performed.
• B. ASH contains sampled data from all sessions that are connected to a database instance at any given moment.
• C. ASH samples data from V$SESSION every second.
• D. An ASH report can be used to identify the service that may be the cause of a transient performance problem.

Answer: AD

NEW QUESTION 4
You have been asked to assess if using column store compression (previously known as hybrid columnar compression or HCC) would help improve the performance of queries on some large tables.
Which three aspects should you consider before you choose this compression method? (Choose three.)

• A. Check whether direct path load operations are used to insert rows in the table.
• B. Check whether the table is frequently queried using full table scans as column store compression only minimizes I/O during full table scans.
• C. Check whether the table is frequently updated because it will have overhead for insert and update operations.
• D. Check whether the table has LOB columns as it will minimize I/O for the queries.
• E. Check whether the table blocks are sparsely populated as this will defragment the blocks.

Answer: ABD

NEW QUESTION 5
In your database, the locally managed tablespace, USERS, has the default space usage alert set to 85% for the warning level and 97% for the critical level.
Which two statements are true? (Choose two.)

• A. Alerts are recorded in both Oracle Enterprise Manager Cloud Control and DBA_OUTSTANDING_ALERTS only when the critical threshold is exceeded.
• B. Alert settings for the warning and critical levels must be disabled before taking the USERS tablespace offline.
• C. Alerts that are triggered are automatically recorded in DBA_ALERT_HISTORY after they are cleared.
• D. Alerts are triggered when the space usage reaches the warning level, again when it reaches the critical level, and yet again when the space usage falls below the critical level.

Answer: BC

NEW QUESTION 6
Which two statements are true about server-generated alerts? (Choose two.)

• A. They are always logged in the alert log.
• B. They are written to a trace file if the TRACE_ENABLED initialization parameter is set toTRUE.
• C. They are generated only when the STATISTICS_LEVEL initialization parameter is set to ALL.
• D. They can be generated for user-defined metric thresholds.
• E. They appear in the DBA_ALERT_HISTORY view whenever corrective action is taken for an alert.

Answer: DE

NEW QUESTION 7
Which three statements are true about the interpretation of an execution plan? (Choose three.)

• A. The cost of the entire plan is indicated by the line with Id 0 and always includes both I/O and CPU resources.
• B. The ROWS column indicates the cardinality of each operation and is always calculated by dividing the total number of rows in the table by the number of distinct values in the column used in the WHERE clause predicate.
• C. A TABLE ACCESS FULL in the Operation column for a query with a WHERE clause occurs only if no index exists for the filter column.
• D. An INDEX UNIQUE SCAN in the Operation column always implies that only one row will be returned.
• E. A HASH JOIN in the Operation column always implies that two tables are joined by using an equijoin.

Answer: BDE

NEW QUESTION 8
Which two statements are true about Compare Period ADDM? (Choose two.)

• A. It is automatically invoked whenever the AWR Compare Period report is invoked.
• B. It is automatically invoked whenever ADDM is run by default.
• C. It verifies if there is any change in the workload or average resource consumption by the SQL executed during the two specified time periods, to ensure 100% accuracy.
• D. It can be used to create a comparison report between the Database Replay workload capture report and the replay report.

Answer: CD

NEW QUESTION 9
Which two statements are true about the interpretation of Buffer Cache Hit Ratio in the Instance Efficiency Percentages section of an AWR report? (Choose two.)

• A. A high value indicates that the buffer cache is adequately sized for the current workload.
• B. Poor hit ratios indicate that a large number of indexed lookups or small table scans are being performed.
• C. A low hit ratio does not necessarily imply that increasing the size of the buffer cache will improve performance.
• D. A high hit ratio may indicate that repeated scanning of the same large table or index is being performed.
• E. A low hit ratio indicates that a KEEP buffer pool should be configured based on the size of the largest object accessed in the buffer cache.

Answer: CD

NEW QUESTION 10
Examine the parameters:

Your database supports a mixed workload and users have dedicated server connections. Users complain about the increased response time of a few queries that are performing large sort operations. On investigation, you notice an increase in the number of multipass work area executions and high number of direct path write wait events.
Which two actions could improve the performance? (Choose two.)

• A. increasing the value of the SORT_AREA_SIZE parameter
• B. increasing the value of the PGA_AGGREGATE_TARGET parameter
• C. enabling Automatic Memory Management for the instance
• D. increasing the size of the default temporary tablespace
• E. using parallel hint in queries performing large sort operations
• F. enabling Automatic Shared Memory Management for the instance

Answer: AF

NEW QUESTION 11
Examine the partial TOP 10 Foreground Events by Total Wait Time section of an AWR report:

What should you examine to diagnose the cause of the top three wait events? (Choose the best answer.)

• A. the V$ACTIVE_SESSION_HISTORY view
• B. the Time Model Statistics section of the AWR report
• C. the SQL statements based on elapsed time from the AWR report
• D. the Latch Activity section
• E. the Segment Statistics section of the AWR report

Answer: B

NEW QUESTION 12
Examine the output of the query executed to diagnose the reason for performance degradation of queries:

Which three factors will you investigate further to identify the cause of the performance degradation? (Choose three.)

• A. Check the number of disk sorts.
• B. Check for the causes of the full table scans.
• C. Check the number of chained or migrated rows.

Answer: ABC

NEW QUESTION 13
You are administering a database that supports a DSS workload. Automatic Shared Memory Management is enabled for the database instance. Users issue queries to perform large soft operations and complain about degraded performance of the queries. On investigation, you notice that the queries are performing multipass work area executions and the I/O contention on one of the temporary tablespaces is very high.
Which two can be possible resolutions for this issue? (Choose two.)

• A. Increase the size of the large pool.
• B. Increase the value of the PGA_AGGREGATE_TARGET parameter.
• C. Create a temporary tablespace group and assign it to users.
• D. Increase the value of the PGA_AGGREGATE_LIMIT parameter.
• E. Create another temporary tablespace and assign it to users.
• F. Enable temporary undo.

Answer: CD

NEW QUESTION 14
Which two statements are true about ADDM? (Choose two.)

• A. It analyzes the performance of a database instance based on the time period covered by the most recent AWR snapshot, and generates recommendations based on hard-coded criteria.
• B. It can analyze performance issues that occurred in past events provided they fall within the AWR retention period.
• C. ADDM resource utilization and cost of analysis depends on the actual load on the database and the number of performance problems analyzed.
• D. It first identifies the performance symptoms, and then refines them to reach the root cause with the singular aim of reducing the DB CPU metric.
• E. It documents only those components and wait classes that are significantly impacting the performance of the database.

Answer: AB

NEW QUESTION 15
Your database supports an online transaction processing (OLTP) workload. The database uses ASM storage. One of the ASM disks goes offline because of hardware failure. When the disk is replaced and then added back to the diskgroup, database performance is affected by rebalance operations.
Which two actions would you recommend to lower the impact of rebalance operations on the performance of the database? (Choose two.)

• A. Increase the number of ASMB processes.
• B. Decrease the value of the ASM_POWER_LIMIT parameter.
• C. Set the DISK_REPAIR_TIME disk attribute to a lower value.
• D. Specify the POWER clause with a lower value in an ALTER DISKGROUP statement.
• E. Set the DISK_REPAIR_TIME disk attribute to a higher value.

Answer: BD

NEW QUESTION 16
For which two requirements can you always use the V$ACTIVE_SESSION_HISTORY view? (Choose two.)

• A. to investigate intermittent performance problems in a session, only when the problem lasted less than five minutes in the last twelve hours
• B. to find the exact number of executions of a specific query in a session in the last two minutes
• C. to identify which module in an application was being executed in a session
• D. to identify a scheduler job that is not responding
• E. to find the amount of Program Global Architecture (PGA) memory being currently consumed by a session

Answer: CE