1z1-084 Questions PDF [2024] Use Valid New dump to Clear Exam [Q27-Q51]

NO.27 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

NO.28 Which two statements are true about space usage in temporary tablespaces?

When a global temporary table instantiation is too large to fit in memory, space is allocated in a temporary tablespace.

Temporary tablespaces setting Includes quotas to limit temporary space used by a session for that Temporary tablespace.

A sort will fail if a sort to disk requires more disk space and no additional extent can be found/allocated in/for the sort segment.

When a session consumes all temporary tablespace storage, then the session would hang until the temporary space used by that session is cleared.

Lack of temporary tablespace space for sort operations can be prevented by using temporary tablespace groups.

NO.29 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;

NO.30 Examine this statement and its corresponding execution plan:

Which phase introduces the CONCATENATION step?

SQL Semantic Check

SQL Execution

SQL Row Source Generation

SQL Transformation

SQL Adaptive Execution

NO.31 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.

NO.32 Which two options are part of a Soft Parse operation?

Syntax Check

SQL Row Source Generation

SQL Optimization

Shared Pool Memory Allocation

Semantic Check

NO.33 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.

NO.34 A database instance is suffering poor I/O performance on two frequently accessed large tables.
No Big Table caching occurs in the database.
Examine these parameter settings:

Which are two actions either one of which will allow Big Table caching to occur?

Increasing DB_BIG_TABLE_CACHE_PERCENT_TARGET to at least 50

Setting DB_KEEP_CACHE_SIZE to at least 50M

Increasing DB_BIG_TABLE_CACHE_PERCENT_TARGET to at least 25

Increasing DB_CACHESIZE to 1 G

Setting PARALLEL_DEGREE_POLICYADAPTIVE

Setting PARALLEL_DEGREE_POLICYAUTO

NO.35 You must write a statement that returns the ten most recent sales. Examine this statement:

Users complain that the query executes too slowly. Examine the statement’s current execution plan:

What must you do to reduce the execution time and why?

Create an index on SALES.TIME_ID to force the return of rows in the order specified by the ORDER BY clause.

Replace the FETCH FIRST clause with ROWNUM to enable the use of an index on SALES.

Collect a new set of statistics on PRODUCT, CUSTOMERS, and SALES because the current stats are inaccurate.

Enable Adaptive Plans so that Oracle can change the Join method as well as the Join order for this query.

Create an index on SALES.CUST_ID to force an INDEX RANGE SCAN on this index followed by a NESTED LOOP join between CUSTOMERS and SALES.

NO.36 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

NO.37 Database performance degraded between 23:15 and 23:30 for the last three nights. The awr snapshot interval is one hour. The AODM report contains nothing about this performance problem.
With which tool can you further analyze this problem?

SQL Performance Analyzer

AWR Compare Periods report

SQL Tuning Advisor

Active Session History report

NO.38 Which application lifecycle phase could be managed reactively?

Design and development

Upgrade or migration

Testing

Production

Deployment

NO.39 A Standard Edition production database has performance problems for two hours on the same day each week.
Which tool must you use to diagnose the problem?

SQL Performance Analyzer

AWR Compare Periods report

Database Replay

Statspack report

NO.40 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.

NO.41 Accessing the SALES tables causes excessive db file sequential read wait events.
Examine this AWR except:

Now, examine these attributes displayed by querying dba_tables:

Finally, examine these parameter settings:

Which two must both be used to reduce these excessive waits?

Partition the SALES table.

Increase PCTFREE for the SALES table.

Re-create the SALES table.

Compress the SALES table.

Coalesce all sales table indexes.

NO.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.

NO.43 You need to collect and aggregate statistics for the ACCTG service and PAYROLL module, and execute:

Where do you find the output of this command?

By viewing V$SERV_MOD_ACT_STATS

In $ORACLE_BASE/diag/rdbms/<db unique name>/<instance name>/trace

By viewing V$SERVICE_STATS

In the current working directory

NO.44 Which two options are part of a Soft Parse operation?

SQL Row Source Generation

SQL Optimization

Semantic Check

Shared Pool Memory Allocation

Syntax Check

NO.45 You must produce a consolidated formatted trace file by combining all trace files generated by all clients for a single service.
Which combination of utilities does this?

Trace Analyzer and Tracsess

Trcsess and TKPROF

Autotrace and TKPROF

TKPROF and Trace Analyzer

NO.46 Buffer cache access is too frequent when querying the SALES table. Examine this command which executes successfully:
ALTER TABLE SALES SHRINK SPACE;
For which access method does query performance on sales improve?

db file scattered read

db file sequential read

index full scan

index range scan

NO.47 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?

NO.48 You use SQL Tuning Advisor to tune a given SQL statement.
The analysis eventually results in the implementation of a SQL Profile.
You then generate the new SQL Profile plan and enforce it using a SQL PlanBaselinebut forget to disable the SQLProfile and a few days later you find out that the SQL Profile is generating a new execution plan.
Which two statements are true?

The existence of two concurrent plan stability methods generates a child cursor for every execution.

The SQL Profiles as well as SQL Plan Baseline are implemented using hints, so they both generate the same plan.

The execution plan is the one enforced by the SQL Profile.

The execution plan is the one enforced by the SQL Plan Baseline.

The SQL Plan Baseline must be accepted in order to be used for the execution plan.

The conflict between the two plan stability methods results in an error.

NO.49 You need to transport performance data from a Standard Edition to an Enterprise Edition database. What is the recommended method to do this?

Export the data by using expdp from Statspack and import it by using
$ORACLE_HOME/rdbms/admin/awrload into the AWRrepository.

Export the data by using expdp from the ftatspack repository and import it by using impdp into the AWR repository.

Export the data by using the expdp utility and parameter file spuexp.par from the Statspack repository and import it by using impdp into Export the data by using expdp from the Statspack repository and import it by using impdp into the AWR repository.

Export the data by using the exp utility and parameter file spuexp.par from the Statspack repository and import it by using imp into a dedicated Statspack schema on the destination.