1z1-084 Exam Questions Get Updated [2025] with Correct Answers [Q27-Q49]

NEW QUESTION 27
Which three statements are true about tuning dimensions and details of v$sys_time_model and DB time?

Statspack cannot account for high CPU time when CPU TIME is a Top 10 event in DB time. When CPU time is high, SQL tuning may improve performance.

Systems in which CPU time is dominant need more tuning that those in which WAIT TIME is dominant.

The proportion of WAIT TIME to CPU TIME always increases with increased system load.

When WAIT TIME is high, instance tuning may improve performance.

Parse Time Elapsed accounts for successful soft and hard parse operations only.

DB Time accounts for all time used by background processes and user sessions.

NEW QUESTION 28
Which three types of statistics are captured by statspack with snap level 6?

Parent and child latches

Optimizer execution plans

Plan usage data

Enqueue statistics

Segment-level statistics

NEW QUESTION 29
Which three statements are true about server-generated alerts?

They are notifications from the Oracle Database Server of an existing or impending problem.

They provide notifications but never any suggestions for correcting the identified problems.

They are logged in the alert log.

They can be viewed only from the Cloud Control Database home page.

Their threshold settings can be modified by using DBMS_SERVER_ALERT.

They may contain suggestions for correcting the identified problems.

Server-generated alerts in Oracle Database are designed to notify DBAs and other administrators about issues within the database environment. These alerts can be triggered by a variety of conditions, including threshold-based metrics and specific events such as ORA- error messages. Here’s how these options align with the statements provided:
* A (True):Server-generated alerts are indeed notifications from the Oracle Database Server that highlight existing or impending issues. These alerts are part of Oracle’s proactive management capabilities, designed to inform administrators about potential problems before they escalate.
* C (True):These alerts are logged in the alert log of the Oracle Database. The alert log is a crucial diagnostic tool that records major events and changes in the database, including server-generated alerts.
This log is often the first place DBAs look when troubleshooting database issues.
* F (True):Server-generated alerts may include suggestions for correcting identified problems. Oracle Database often provides actionable advice within these alerts to assist in resolving issues more efficiently. These suggestions can range from adjusting configuration parameters to performing specific maintenance tasks.
Options B, D, and E do not accurately describe server-generated alerts:
* B (False):While the statement might have been true in some contexts, Oracle’s server-generated alerts often include corrective suggestions, making this statement incorrect.
* D (False):Server-generated alerts can be viewed from various interfaces, not just the Cloud Control Database home page. They are accessible through Enterprise Manager, SQL Developer, and directly within the database alert log, among other tools.
* E (False):While it’s true that threshold settings for some alerts can be modified, the method specified, usingDBMS_SERVER_ALERT, is not correct. Threshold settings are typically adjusted through Enterprise Manager or by modifying specific initialization parameters directly.
References:
* Oracle Database Documentation:Oracle Database 19c: Performance Management and Tuning
* Oracle Base: Alert Log and Trace Files
* Oracle Support:Understanding and Managing Server-Generated Alerts

NEW QUESTION 30
Which two statements are true about the use and monitoring of Buffer Cache Hit ratios and their value in tuning Database I/O performance?

The performance of workloads that primarily generate full table scans and fast full index scans are always affected by the cache hit ratio.

A 99% cache hit ratio can be observed for database instances which have very poor I/O performance.

The buffer cache advisory view v$db_cache_advice provides advice on cache hit ratios appropriate for the instance workload.

Both the RECYCLE and KEEP buffer caches should always have a very high cache hit ratio.

A 60% cache hit ratio can be observed for database instances which have very good I/O performance.

NEW QUESTION 31
Examine this AWRreport excerpt:

You must reduce the impact of database I/O, without increasing buffer cache size and without modifying the SQL statements.
Which compression option satisfies this requirement?

MN STORE COMPRESS FOR QUERY LOW

STORE COMPRESS

ROW STORE COMPRESS ADVANCED

COLUMN STORE COMPRESS FOR QUERY HIGH

NEW QUESTION 32
Examine this AWR report excerpt:

You must reduce the impact of database I/O, without increasing buffer cache size and without modifying the SQL statements.
Which compression option satisfies this requirement?

MN STORE COMPRESS FOR QUERY LOW

STORE COMPRESS

ROW STORE COMPRESS ADVANCED

COLUMN STORE COMPRESS FOR QUERY HIGH

NEW QUESTION 33
Which procedure gathers statistics that are always used in the generation of any execution plan?

DBMS_STATS.GATHER_DICTIONARY_STATS

DBMS_STATS.GATHER_FIXED_ OBJECTS_STATS

DBMS_STATS.GATHER_DATABASE_STATS

DBMS_STATS.GATHER_SYSTEM_STATS

NEW QUESTION 34
Examine this command:

What is the maximum number of baselines generated by this command that you can have at any given time?

1

3

52

5

NEW QUESTION 35
Examine this code block, which executes successfully:
DBMS_SERVER_ALERT. SET_THRESHOLD (
DBMS_SERVER_ALERT.CPU_TIME_PER_CALL, DBMS_SERVER_ALERT. OPERATOR_GE, ‘8000’, DBMS_SERVER_ALERT.OPERATOR_GE, ‘10000’, 1, 2, ‘inst1’, DBMS_SERVER_ALERT.OBJECT_TYPE_SERVICE, ‘main.regress.rdbms.dev.us.example.com’) ;

What will happen?

A warning alert will be issued when CPU time exceeds 1 minute for each user call.

A critical alert will be issued when CPU time exceeds 10000 microseconds for each user call.

A warning alert will be issued only when CPU time exceeds 10000 microseconds for each user call.

A critical alert will be issued when CPU time exceeds 2 minutes for each user call.

NEW QUESTION 36
Which two options are part of a Soft Parse operation?

Syntax Check

SQL Row Source Generation

SQL Optimization

Shared Pool Memory Allocation

Semantic Check

NEW QUESTION 37
Which Optimizer component helps decide whether to use a nested loop join or a hash join in an adaptive execution plan?

Statistics Feedback

SQL Plan Directives

Statistics Collector

Automatic Reoptimization

Dynamic Statistics

NEW QUESTION 38
An Oracle 19c database uses default values for all optimizer initialization parameters.
After a table undergoes partition maintenance, a large number of wait events occur for:
cursor: pin S wait on X
Which command reduces the number of these wait events?

ALTER SYSTEM SET CURSOR_SHARING = FORCE;

ALTER SYSTEM SET CURSOR_SPACE_FOR_TIME – TRUE;

ALTER SYSTEM SET CURSOR_INVALIDATION = DEFERRED;

ALTER SYSTEM SET SESSION CACHED CURSORS = 500;

NEW QUESTION 39
What are the least elevated values of statistics_level and C0NTR0LJ4ANAGEMENT_PACK_ACCESS that allow the usage of Monitoring of Database Operations?

STATISTICS_LEVEL=ALL and
CONTROL_MANAGEMENT_PACK_ACCESS=DIAGOSTIC+TUNING

STATISTICS_LEVEL=BASIC and CONTROL_MANAGEMENT_PACK ACCESS=DIAGOSTIC

STATISTICS_LEVEL=TYPICAL and CONTROL_MANAGEMENT_PACK_ACCESS-
DIAGOSTIC*TUNING

STATISTICS_LEVEL=TYPICAL and CONTROL_MANAGEMENT_PACK_ACCESS=DIAGOSTIC

NEW QUESTION 40
You manage a 19c database with default optimizer settings.
This statement is used extensively as subquery in the application queries:
SELECT city_id FROM sh2.sales WHERE city_id=:Bl
You notice the performance of these queries is often poor and, therefore, execute:
SELECT city_id,COUNT(*) FROM sh2.sales GROUP BY city_id;
Examine the results:

There is no index on the CITY_ID column.
Which two options improve the performance?

Generate frequency histograms on the CITY__ID column.

Create an index on the CITY IP column.

Use a SQL Profile to enforce the appropriate plan.

Force the subquery to use dynamic sampling.

Activate the adaptive plans.

NEW QUESTION 41
What is the right time to stop tuning an Oracle database?

When the allocated budget for performance tuning has been exhausted

When all the concurrency waits are eliminated from the Top 10

When the buffer cache and library cache hit ratio is above 95%

When the I/O is less than 10% of the DB time

When the tuning goal has been met

NEW QUESTION 42
Which two statements are true about cursor sharing?

Setting Cursor_sharing to FORCE can result in a plan that is suboptimal for the majority of values bound to a bind variable when executing a cursor with one or more bind variables.

Adaptive Cursor Sharing guarantees that a suboptimal plan will never be used on any execution of a SQL statement.

Setting optimizer_capture_sql_plan_baselines to TRUE loads all adaptive plans for the same statement into the cursor cache.

Setting cursor_sharing to EXACT prevents Adaptive Cursor Sharing from being used.

Adaptive Cursor Sharing requires histograms on filtered columns, used in equality predicates, to allow different execution plans to be generated for statements whose bound values would normally generate different plans at hard parse time.

NEW QUESTION 43
An Oracle 19c database uses default values for all optimizer initialization parameters.
After a table undergoes partition maintenance, a large number of wait events occur for:
cursor: pin S wait on X
Which command reduces the number of these wait events?

ALTER SYSTEM SET CURSOR_SHARING = FORCE;

ALTER SYSTEM SET CURSOR_SPACE_FOR_TIME – TRUE;

ALTER SYSTEM SET CURSOR_INVALIDATION = DEFERRED;

ALTER SYSTEM SET SESSION CACHED CURSORS = 500;

NEW QUESTION 44
You must configure and enable Database Smart Flash Cache for a database.
You configure these flash devices:

Examine these parameter settings:

What must be configured so that the database uses these devices for the Database Smart Flash Cache?

Set DB_FLASH_CACHE_SIZE to 192G and MEMORY_TARGET to 256G.

Set DB_FLASH_CACHE_SIZE parameter to 192G.

Disable Automatic Memory Management and set SGA_TARGET to 256G.

Set DB_FLASH_CACHE_SIZE to 256G and change device /dev/sdk to 128G.

Set DB_FLASH_CACHE_SIZE parameter to 128G, 64G.

NEW QUESTION 45
SGA_TARGET and PGA_AGGREGATE_TARGET are configured to nonzero values.
MEMORY_target is then set to a nonzero value but memory_MAX_TARGET is not set.
Which two statements are true?

NEW QUESTION 46
Which two actions can cause invalidation or loss of one or more results in the SQL Query Result Cache?

One or more results were aged out of the result cache.

result_cache_max_size is set dynamically to 0.

A request was made by the RCBG background of a non-RAC database.

A request was made by the RCBG background process in a physical standby database that is opened read only and whose primary has a result cache.

Decreasing the value set for RESULT_CACHE_REMOTE_EXPIRATION.

NEW QUESTION 47
Which two Oracle Database features use database services?

Oracle Automatic Reoptimization

Database Resource Manager

Oracle SQL Performance Management

Oracle SQL Tuning Advisor

Oracle Scheduler

NEW QUESTION 48
Which two statements are true about the use and monitoring of Buffer Cache Hit ratios and their value in tuning Database I/O performance?

A 99% cache hit ratio can be observed for database instances which have very poor I/O performance.

A 60% cache hit ratio can be observed for database instances which have very good I/O performance.

The performance of workloads that primarily generate full table scans and fast full index scans are always affected by the cache hit ratio.

The buffer cache advisory view v$db_cache_advice provides advice on cache hit ratios appropriate for the instance workload.

Both the RECYCLE and KEEP buffer caches should always have a very high cache hit ratio.

NEW QUESTION 49
Database performance has degraded recently.
index range scan operations on index ix_sales_time_id are slower due to an increase in buffer gets on sales table blocks.
Examine these attributes displayed by querying DBA_TABLES:

Now, examine these attributes displayed by querying DBA_INDEXES:

Which action will reduce the excessive buffer gets?