合格させる1z1-084テスト問題集で[2024年07月22日]に更新された57問あります [Q31-Q53]

合格させる1z1-084テスト問題集で[2024年07月22日]に更新された57問あります

Oracle 1z1-084実際の問題と100%カバー率でリアル試験問題

Oracle 1Z0-084試験は、Oracle Database 19cの経験があり、データベース管理の基本的な概念に精通している個人を対象としています。候補者は、SQL、データベースアーキテクチャ、パフォーマンスチューニング技術に強い理解を持っている必要があります。試験を受ける前に、候補者は少なくとも2年間Oracle Database 19cでの作業経験を持っていることが推奨されます。

 

質問 # 31
Which application lifecycle phase could be managed reactively?

• A. Upgrade or migration
• B. Deployment
• C. Production
• D. Testing
• E. Design and development

正解：C

解説：
The production phase of the application lifecycle is often managed reactively. While proactive measures and performance tuning are essential, unforeseen issues can arise in production that require immediate attention and resolution. Reactive management involves monitoring performance and responding to issues as they occur, ensuring the application maintains acceptable performance levels for end-users.
References
* Oracle Database 19c Performance Tuning Guide - Reactive Tuning

質問 # 32
Examine these commands, which execute successfully:

Which statement is true?

• A. AWR- snapshots in all pluggable databases will be purgedautomatically after every 60 mins.
• B. AD DM is enabled for all pluggable databases.
• C. ADDM, AWR, and ASH reports can be purged automatically.
• D. AWR snapshots can be purged manually in pluggable databases.

正解：D

解説：
TheDBMS_WORKLOAD_REPOSITORY.MODIFY_SNAPSHOT_SETTINGSprocedure allows setting attributes related to AWR snapshots. While the interval setting controls the frequency of snapshot generation, purging them is a separate process that can be managed either automatically (with retention settings) or manually.References:
* Oracle Database PL/SQL Packages and Types Reference, 19c
* Oracle Multitenant Administrator's Guide, 19c

質問 # 33
Which three types of statistics are captured by statspack with snap level 6?

• A. Enqueue statistics
• B. Parent and child latches
• C. Optimizer execution plans
• D. Plan usage data
• E. Parent and child latches
• F. Segment-level statistics

正解：A、B、F

解説：
Statspack is a performance diagnostic tool provided by Oracle prior to the introduction of the Automatic Workload Repository (AWR). At snap level 6, Statspack captures the following types of statistics:
* A (Correct):Parent and child latches are captured. Latch statistics provide information about contention for latches, which are low-level serialization mechanisms used by Oracle.
* E (Correct):Enqueue statistics, which provide information on the waits for locks that manage the concurrency between users.
* F (Correct):Segment-level statistics, which provide detailed information on database segments such as tables, indexes, etc., to identify I/O and contention issues.
* C (Incorrect):While optimizer execution plans are an essential aspect of performance tuning, detailed execution plan capture is not part of the Statspack report at level 6.
* D (Incorrect):Plan usage data refers to how frequently a plan is being used, which is more associated with AWR and not typically captured in Statspack reports.
References:
* Oracle Database Performance Tuning Guide:Using Statspack

質問 # 34
Which three statements are true about tuning dimensions and details of v$sys_time_model and DB time?

• A. Systems in which CPU time is dominant need more tuning that those in which WAIT TIME is dominant.
• B. The proportion of WAIT TIME to CPU TIME always increases with increased system load.
• C. Parse Time Elapsed accounts for successful soft and hard parse operations only.
• D. DB Time accounts for all time used by background processes and user sessions.
• E. When WAIT TIME is high, instance tuning may improve performance.
• F. 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.

正解：D、E、F

解説：
A: Statspack is a performance diagnostic tool that can help identify high CPU usage issues. High CPU time may indicate that SQL statements need to be tuned for better performance.
D: High wait times can often be reduced by instance tuning, such as adjusting database parameters or improving I/O performance.
F: DB Time is a cumulative time metric that includes the time spent by both user sessions and background processes executing database calls.References:
* Oracle Database Performance Tuning Guide, 19c
* Oracle Database Concepts, 19c

質問 # 35
You need to transport performance data from a Standard Edition to an Enterprise Edition database. What is the recommended method to do this?

• A. Export the data by using expdp from the ftatspack repository and import it by using impdp into the AWR repository.
• B. 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.
• C. 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.
• D. Export the data by using expdp from Statspack and import it by using
  $ORACLE_HOME/rdbms/admin/awrload into the AWRrepository.

正解：C

解説：
To transport performance data from an Oracle Database Standard Edition, which uses Statspack, to an Enterprise Edition database, which uses AWR, you must consider the compatibility of data structures and repository schemas between these tools. The recommended method is:
* D (Correct):Export the data using theexputility with a parameter file appropriate for Statspack (like spuexp.par) from the Statspack repository and import it into a dedicated Statspack schema on the destination. Since Statspack and AWR use different schemas, it's not recommended to import Statspack data directly into the AWR repository.
The other options are incorrect because:
* A (Incorrect):expdpis not designed to export from Statspack, andawrloadis intended for loading from an AWR export file, not a Statspack export.
* B (Incorrect):Althoughexpdpandimpdpare used for exporting and importing data, the AWR repository schema is different from the Statspack schema, so importing Statspack data directly into the AWR repository is not recommended.
* C (Incorrect):Usingexpdpto export from Statspack and then importing directly into the AWR repository is not the correct approach due to the schema differences between Statspack and AWR.
References:
* Oracle Database Performance Tuning Guide:Migrating from Statspack to AWR

質問 # 36
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?

• A. Collect a new set of statistics on PRODUCT, CUSTOMERS, and SALES because the current stats are inaccurate.
• B. Create an index on SALES.TIME_ID to force the return of rows in the order specified by the ORDER BY clause.
• C. Replace the FETCH FIRST clause with ROWNUM to enable the use of an index on SALES.
• D. 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.
• E. Enable Adaptive Plans so that Oracle can change the Join method as well as the Join order for this query.

正解：B

解説：
The execution plan shows a full table access for theSALEStable. To reduce the execution time, creating an index onSALES.TIME_IDwould be beneficial as it would allow the database to quickly sort and retrieve the most recent sales without the need to perform a full table scan, which is I/O intensive and slower. By indexing TIME_ID, which is used in theORDER BYclause, the optimizer can take advantage of the index to efficiently sort and limit the result set to the ten most recent sales.
* B (Incorrect):ReplacingFETCH FIRSTwithROWNUMwould not necessarily improve the performance unless there is an appropriate index that the optimizer can use to avoid sorting the entire result set.
* C (Incorrect):There is no indication that the current statistics are inaccurate; hence, collecting new statistics may not lead to performance improvement.
* D (Incorrect):While adaptive plans can provide performance benefits by allowing the optimizer to adapt the execution strategy, the main issue here is the lack of an index on theORDER BYcolumn.
* E (Incorrect):Creating an index onSALES.CUST_IDcould improve join performance but would not address the performance issue caused by the lack of an index on theORDER BYcolumn.
References:
* Oracle Database SQL Tuning Guide:Managing Indexes
* Oracle Database SQL Tuning Guide:Using Indexes and Clusters

質問 # 37
What is the right time to stop tuning an Oracle database?

• A. When the buffer cache and library cache hit ratio is above 95%
• B. When the I/O is less than 10% of the DB time
• C. When all the concurrency waits are eliminated from the Top 10
• D. When the allocated budget for performance tuning has been exhausted

正解：D

解説：
The right time to stop tuning an Oracle database is often determined by the point of diminishing returns - when the cost of further tuning (in terms of time, resources, or money) exceeds the performance benefits gained.
This is often related to the budget allocated for performance tuning.
* A (Correct):When the allocated budget for performance tuning has been exhausted, it may be time to stop tuning unless the benefits of further tuning justify requesting additional budget.
* B (Incorrect):Eliminating all concurrency waits from the Top 10 is an unrealistic goal since some waits are inevitable and can occur due to application design, which might not be possible to eliminate completely.
* C (Incorrect):The buffer cache and library cache hit ratio being above 95% does not necessarily indicate that the database is fully optimized. Hit ratios are not reliable indicators of database performance and should not be used as sole criteria to end tuning efforts.
* D (Incorrect):Having I/O less than 10% of DB time is not a definitive indicator to stop tuning. It is essential to consider the overall performance goals and whether they have been met rather than focusing solely on I/O metrics.
References:
* Oracle Database Performance Tuning Guide:Introduction to Performance Tuning
* Oracle Database 2 Day + Performance Tuning Guide:Understanding the Tuning Process

質問 # 38
Which two options are part of a Soft Parse operation?

• A. SQL Row Source Generation
• B. Syntax Check
• C. Shared Pool Memory Allocation
• D. Semantic Check
• E. SQL Optimization

正解：D

質問 # 39
Examine this statement and its corresponding execution plan:

Which phase introduces the CONCATENATION step?

• A. SQL Adaptive Execution
• B. SQL Row Source Generation
• C. SQL Transformation
• D. SQL Semantic Check
• E. SQL Execution

正解：C

解説：
The CONCATENATION step in an execution plan is introduced during the SQL Transformation phase. This phase is part of the optimizer's query transformations which can include various techniques to rewrite the query for more efficient execution. The CONCATENATION operation is used to combine the results of two separate SQL operations, typically when there is an OR condition in the WHERE clause, as seen in the provided query.
References:
* Oracle Database SQL Tuning Guide, 19c
* Oracle Database Concepts, 19c

質問 # 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?

• A. Use a SQL Profile to enforce the appropriate plan.
• B. Generate frequency histograms on the CITY__ID column.
• C. Create an index on the CITY IP column.
• D. Activate the adaptive plans.
• E. Force the subquery to use dynamic sampling.

正解：B、C

解説：
In this scenario, creating an index and generating frequency histograms are two methods that can potentially improve performance:
* A (Correct):Generating frequency histograms on theCITY_IDcolumn can help the optimizer make better decisions regarding the execution plan, especially if the data distribution is skewed. Histograms provide the optimizer with more detailed information about the data distribution in a column, which is particularly useful for columns with non-uniform distributions.
* B (Correct):Creating an index on theCITY_IDcolumn would speed up queries that filter on this column, especially if it's used frequently in the WHERE clause as a filter. An index would allow for an index range scan instead of a full table scan, reducing the I/O and time needed to execute such queries.
* C (Incorrect):While SQL profiles can be used to improve the performance of specific SQL statements, they are usually not the first choice for such a problem, and creating a profile does not replace the need for proper indexing or statistics.
* D (Incorrect):Forcing the subquery to use dynamic sampling might not provide a consistent performance benefit, especially if the table statistics are not representative or are outdated. However, dynamic sampling is not as effective as having accurate statistics and a well-chosen index.
* E (Incorrect):Adaptive plans can adjust the execution strategy based on the conditions at runtime.
While they can be useful in certain scenarios, in this case, creating an index and ensuring accurate statistics would likely provide a more significant performance improvement.
References:
* Oracle Database SQL Tuning Guide:Managing Optimizer Statistics
* Oracle Database SQL Tuning Guide:Using Indexes and Clusters

質問 # 41
Examine this command:

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

• A. 0
• B. 1
• C. 2
• D. 3

正解：D

解説：
TheDBMS_WORKLOAD_REPOSITORY.CREATE_BASELINE_TEMPLATEprocedure is used to create a repeating baseline template in the Automatic Workload Repository (AWR). This template will generate baselines for a specified duration of time on a repeating schedule. Theparameters of the CREATE_BASELINE_TEMPLATEprocedure include the start and end times, as well as the day of the week and hour in the day when the baseline should be captured.
Given that the command specifies a repeating baseline every Monday at 5 PM with a duration of 3 hours and it expires after 30 days, the number of baselines generated by this command that you can have at any given time depends on how many Mondays fall within the most recent 30-day period.
Since the maximum number of Mondays that can occur within any 30-day period is 5 (four to five weeks), but considering the baseline has a duration of 3 hours and starts every Monday at 5 PM, only one baseline for each Monday can exist at a time. However, since baselines are preserved for 30 days, you could have multiple instances of Monday baselines preserved at a time.
* A (Incorrect):There can be more than one baseline at a time because the template will generate a baseline for every Monday during the 30-day expiration period.
* B (Incorrect):There will be more than three baselines because the template creates a baseline for every Monday within the 30-day expiration period.
* C (Correct):Over a 30-day period, considering the duration of the baselines and their frequency, you could have up to a maximum of 52 baselines if you consider the entire year.
* D (Incorrect):There is no option that restricts the number of baselines to 5 specifically, the answer relies on the calculation of how many baselines can exist over a period of time considering their expiration.
References:
* Oracle Database PL/SQL Packages and Types Reference:DBMS_WORKLOAD_REPOSITORY

質問 # 42
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?

• A. Re-create the SALES table using the columns in IX_SALES_TIME_ID as the hash partitioning key.
• B. Re-create index IX_SALES_TIME_ID using ADVANCED COMPRESSION.
• C. Partition index IX_SALES_TIME_ID using hash partitioning.
• D. Re-create the SALES table sorted in order of index IX_SALES_TIME_ID.

正解：B

解説：
Given that index range scan operations onIX_SALES_TIME_IDare slower due to an increase in buffer gets, the aim is to improve the efficiency of the index access. In this scenario:
* B (Correct):Re-creating the index usingADVANCED COMPRESSIONcan reduce the size of the index, which can lead to fewer physical reads (reduced I/O) and buffer gets when the index is accessed, as more of the index can fit into memory.
The other options would not be appropriate because:
* A (Incorrect):Re-creating theSALEStable sorted in order of the index might not address the issue of excessive buffer gets. Sorting the table would not improve the efficiency of the index itself.
* C (Incorrect):Using the columns inIX_SALES_TIME_IDas a hash partitioning key for theSALES table is more relevant to data distribution and does not necessarily improve index scan performance.
* D (Incorrect):Hash partitioning the index is generally used to improve the scan performance in a parallel query environment, but it may not reduce the number of buffer gets in a single-threaded query environment.
References:
* Oracle Database SQL Tuning Guide:Managing Indexes
* Oracle Database SQL Tuning Guide:Index Compression

質問 # 43
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?

• A. Partition the SALES table.
• B. Compress the SALES table.
• C. Re-create the SALES table.
• D. Coalesce all sales table indexes.
• E. Increase PCTFREE for the SALES table.

正解：A、B

解説：
The AWR excerpt points to excessive physical reads on the SALES table and index, suggesting the need for optimizing table storage and access.
Partitioning the SALES table (A) can reduce 'db file sequential read' waits by breaking down the large SALES table into smaller, more manageable pieces. This can localize the data and reduce the I/O necessary for query operations.
Compressing the SALES table (D) can also help reduce I/O by minimizing the amount of data that needs to be read from disk. This can also improve cache utilization and reduce the 'db file sequential read' waits.
References:
* Oracle Database VLDB and Partitioning Guide, 19c
* Oracle Database Administrator's Guide, 19c
These changes are recommended based on Oracle's best practices for managing large tables and reducing I/O waits, ensuring better performance and efficiency.

質問 # 44
Which Optimizer component helps decide whether to use a nested loop join or a hash join in an adaptive execution plan?

• A. SQL Plan Directives
• B. Statistics Feedback
• C. Statistics Collector
• D. Automatic Reoptimization
• E. Dynamic Statistics

正解：C

解説：
In an adaptive execution plan, the Optimizer makes runtime decisions between nested loop and hash joins using a statistics collector. The collector is a row source that collects statistics about the rows it processes and can adapt the plan based on the number of rows processed.
References:
* Oracle Database SQL Tuning Guide, 19c

質問 # 45
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?

• A. db file sequential read
• B. index range scan
• C. db file scattered read
• D. index full scan

正解：A

解説：
The SHRINK SPACE operation compacts the table, which can reduce fragmentation and thus improve performance for sequential reads of the table. This operation could improve full table scans, which are typically associated with db file sequential read wait events.
References:
* Oracle Database Administrator's Guide, 19c

質問 # 46
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?

• A. SQL Tuning Advisor
• B. AWR Compare Periods report
• C. SQL Performance Analyzer
• D. Active Session History report

正解：D

解説：
The Active Session History (ASH) report is a tool that provides detailed information about active sessions for the time period specified. Since the AWR snapshot interval is one hour and does not capture the granularity needed for this issue, ASH reports aremore suitable as they contain more granular data for sessions that were active during the period of interest.
References:
* Oracle Database Performance Tuning Guide, 19c

質問 # 47
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. A 60% cache hit ratio can be observed for database instances which have very good I/O performance.
• B. A 99% cache hit ratio can be observed for database instances which have very poor I/O performance.
• C. Both the RECYCLE and KEEP buffer caches should always have a very high cache hit ratio.
• D. The performance of workloads that primarily generate full table scans and fast full index scans are always affected by the cache hit ratio.
• E. The buffer cache advisory view v$db_cache_advice provides advice on cache hit ratios appropriate for the instance workload.

正解：B、E

解説：
A high buffer cache hit ratio typically indicates that the database is effectively using the buffer cache and does not often need to read data from disk. However, this metric alone is not a reliable indicator of the I/O performance of the database for several reasons:
* Full table scans and fast full index scans (A) can bypass the buffer cache by design if the blocks are not
* deemed reusable shortly, which can impact the cache hit ratio.
* A high cache hit ratio (B) can be misleading if the database performance is poor due to other factors, such as inefficient queries or contention issues.
* The buffer cache advisory (C) is a more valuable tool for understanding the potential impact of different cache sizes on the database's I/O performance. It simulates scenarios with different cache sizes and provides a more targeted recommendation.
* The RECYCLE and KEEP buffer caches (D) are specialized caches designed for certain scenarios.
While high hit ratios can be beneficial, they are not universally required; some workloads might not be significantly impacted by lower hit ratios in these caches.
* A lower cache hit ratio (E) does not necessarily mean poor I/O performance. In some cases, a system with a well-designed storage subsystem and efficient queries might perform well even with a lower cache hit ratio.
References
* Oracle Database 19c Performance Tuning Guide - Buffer Cache Hit Ratio
* Oracle Database 19c Performance Tuning Guide - v$db_cache_advice

質問 # 48
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?

• A. Set DB_FLASH_CACHE_SIZE to 256G and change device /dev/sdk to 128G.
• B. Set DB_FLASH_CACHE_SIZE parameter to 192G.
• C. Set DB_FLASH_CACHE_SIZE to 192G and MEMORY_TARGET to 256G.
• D. Disable Automatic Memory Management and set SGA_TARGET to 256G.
• E. Set DB_FLASH_CACHE_SIZE parameter to 128G, 64G.

正解：E

解説：
To configure and enable Database Smart Flash Cache, you must set the DB_FLASH_CACHE_SIZE parameter to reflect the combined size of the flash devices youintend to use for the cache. In this scenario, two flash devices are configured: /dev/sdj with 128G and /dev/sdk with 64G.
* Determine the combined size of the flash devices intended for the Database Smart Flash Cache. In this case, it's 128G + 64G = 192G.
* However, Oracle documentation suggests setting DB_FLASH_CACHE_SIZE to the exact sizes of the individual devices, separated by a comma when multiple devices are used.
* Modify the parameter in the database initialization file (init.ora or spfile.ora) or using an ALTER SYSTEM command. Here's the command for altering the system setting:
ALTER SYSTEM SET DB_FLASH_CACHE_SIZE='128G,64G' SCOPE=SPFILE;
* Since this is a static parameter, a database restart is required for the changes to take effect.
* Upon database startup, it will allocate the Database Smart Flash Cache using the provided sizes for the specified devices.
It is important to note that MEMORY_TARGET and MEMORY_MAX_TARGET parameters should be configured independently of DB_FLASH_CACHE_SIZE. They control the Oracle memory management for the SGA and PGA, and do not directly correlate with the flash cache configuration.
References
* Oracle Database 19c Documentation on Database Smart Flash Cache
* Oracle Support Articles and Community Discussions on DB_FLASH_CACHE_SIZE Configuration

質問 # 49
This error occurred more than four hours ago in the database:
ORA-04036 PGA memory used by theinstance exceedsPGA_AGGREGATE_LIMIT
You want to know which process and query were at fault.
Which two views should you use for this purpose?

• A. DBA_HIST_PGASTAT
• B. DBA_HIST_ACTIVE_SESS_HISTORY
• C. DBA_HIST_SQLTEXT
• D. DBA_HIST_PROCESS_MEM_SUMMARY
• E. DBA_HIST_SQLSTAT

正解：B、D

解説：
To investigate the cause of the ORA-04036 error, which indicates that PGA memory usage exceeds the PGA_AGGREGATE_LIMIT, the appropriate views to consult are DBA_HIST_ACTIVE_SESS_HISTORYandDBA_HIST_PROCESS_MEM_SUMMARY.
* DBA_HIST_ACTIVE_SESS_HISTORY:This view provides historical information about active sessions in the database. It includes details about the SQL executed, the execution context, and the resources consumed by each session. By examining this view, you can identify the specific sessions and SQL queries that were active and potentially consuming excessive PGA memory around the time the ORA-04036 error occurred.
* DBA_HIST_PROCESS_MEM_SUMMARY:This view contains historical summaries of memory usage by processes. It can help in identifying the processes that were consuming a significant amount of PGA memory, leading to the ORA-04036 error. This view provides aggregated memory usage information over time,making it easier to pinpoint the processes responsible for high PGA memory consumption.
Together, these views offer a comprehensive overview of the memory usage patterns and specific queries or processes that might have contributed to exceeding thePGA_AGGREGATE_LIMIT, resulting in the ORA-04036 error.
References:
* Oracle Database Reference:DBA_HIST_ACTIVE_SESS_HISTORY
* Oracle Database Reference:DBA_HIST_PROCESS_MEM_SUMMARY
* Oracle Database Performance Tuning Guide:Managing Memory

質問 # 50
You want to reduce the amount of db file scattered read that is generated in the database.You execute the SQL Tuning Advisor against the relevant workload. Which two can be part of the expected result?

• A. recommendations regarding partitioning the tables
• B. recommendations regarding the creation of materialized views
• C. recommendations regarding the creation of SQL Patches
• D. recommendations regarding rewriting the SQL statements
• E. recommendations regarding the creation of additional indexes

正解：B、E

解説：
The SQL Tuning Advisor provides recommendations for improving SQL query performance. This may include suggestions for creating additional indexes to speed up data retrieval and materialized views to precompute and store query results.References:
* Oracle Database SQL Tuning Guide, 19c

質問 # 51
Which two statements are true about disabling Automatic Shared Memory Management (ASMM)?

• A. The SGA size remains unaffected after disabling ASMM.
• B. It requires a database instance restart to take effect.
• C. Both SGA_TARGET and SGA_MAX_SIZE must be set to zero.
• D. All SGA components retain their current sizes at the time of disabling.
• E. All SGA components excluding fixed SGA and other internal allocations are readjusted immediately after disabling ASMM.
• F. All auto-tuned SGA components are reset to their original user-defined values.

正解：A、D

解説：
When ASMM is disabled, the sizes of the automatically managed SGA components remain at their current values. ASMM is controlled by theSGA_TARGETparameter. IfSGA_TARGETis set to a non-zero value, ASMM is enabled and Oracle will automatically manage the sizes of the various SGA components. When ASMM is disabled, by settingSGA_TARGETto zero, the SGA components that were automatically sized will retain their current sizes rather than being reset to their original user-defined values. The overall size of the SGA remains the same unless manually changed by modifying individual component sizes or SGA_MAX_SIZE.
References:
* Oracle Database Administration Guide, 19c
* Oracle Database Performance Tuning Guide, 19c

質問 # 52
Which two actions can cause invalidation or loss of one or more results in the SQL Query Result Cache?

• A. A request was made by the RCBG background of a non-RAC database.
• B. One or more results were aged out of the result cache.
• C. Decreasing the value set for RESULT_CACHE_REMOTE_EXPIRATION.
• D. result_cache_max_size is set dynamically to 0.
• E. 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.

正解：B、D

解説：
The SQL Query Result Cache stores the results of queries and PL/SQL function calls for reuse. However, entries in the result cache can be invalidated or lost under certain conditions:
A: Results can be aged out of the cache when the cache becomes full and new results need to be stored. This process ensures that the cache does not exceed its allocated memory and that it contains the most recently used entries.
B: Setting theRESULT_CACHE_MAX_SIZEparameter to 0 will effectively disable the result cache and all cached results will be lost, as Oracle will no longer allocate any memory to the result cache.
References:
* Oracle Database Performance Tuning Guide, 19c

質問 # 53
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Oracle 1Z0-084認定試験は、Oracle Database 19cパフォーマンスとチューニング管理におけるスキルと知識を検証したいITプロフェッショナルにとって貴重な認定試験です。この試験は、パフォーマンスチューニングのコンセプト、ベストプラクティス、ツールの理解をテストするために設計されています。また、データベースのパフォーマンス問題を分析し、最適なチューニングソリューションを提案する能力を検証するためにも設計されています。Oracle 1Z0-084認定試験に合格することは、候補者がOracle Database 19cのパフォーマンスを管理するために必要なスキルと知識を持っていることを示すものです。

Oracle 1Z0-084試験は挑戦的であり、パフォーマンスとチューニングの概念の徹底的な理解とOracle Database 19cの深い知識が必要です。試験は120分間で85問から構成され、合格点は62％です。試験に合格した候補者は、雇用主に高く評価され、Oracleデータベースの分野で業界標準の認定として認識されるパフォーマンスとチューニング管理のスキルと知識を証明します。

 

Oracle 1z1-084リアルな2024年最新のブレーン問題集で模擬試験問題集：https://www.passtest.jp/Oracle/1z1-084-shiken.html

1z1-084無料試験問題と解答PDF更新されたのは2024年07月：https://drive.google.com/open?id=1sMBBPwQu6_0SkS4vToF-k9wwUSIVxvQl