Question 1
Multiple choice
Which two completely prevent a Smart Scan from occurring?
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A
querying a table containing many chained rows
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B
querying a table containing many migrated rows
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C
performing a minimum or maximum function on an indexed column
-
D
performing a Fast Full Index scan on a reverse key index
-
E
referencing more than 255 columns form an OLTP compressed table in a query
-
F
querying a table containing a JSON column
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Correct answersB, E
ExplanationExplanation:
B: Migrated Rows is a special case of chained rows. Migrated rows still affect performance, as they do in conventional storage situations, but with the additional overhead of reducing the beneficial effects of "Smart Scan" in addition to increasing the number of I/Os E: Smart Scans - broadly speaking and ignoring edge cases - can only transport a maximum of 254 columns from a single (non-HCC) segment. Requesting more columns will simply disable Smart Scans for that segment. An interesting limitation to Exadata Smart Scans - if more than 254 columns from a table (not HCC compressed, more on that in moment) need to be projected, Smart Scans for that particular segment will be disabled and Exadata will fall back to conventional I/O. This means that the number of columns in the projection clause can make a significant difference to performance, since only Smart Scans allow taking advantage of offloading and particularly avoiding I/O via Storage Indexes. Incorrect Answers:
A: Smart scan can cope with some cases of chained rows References:
http://oracle-randolf.blogspot.se/2013/01/exadata-smart-scan-projection-limitation.html
Question 2
Multiple choice
Which two network switch failure scenarios on a standalone Exadata Database Machine X5-2 Full Rack will affect database availability?
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A
failure of the Ethernet switch only
-
B
failure of both the InfiniBand leaf switches
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C
failure of a single InfiniBand leaf switch and the Ethernet switch
-
D
failure of a single InfiniBand leaf switch
-
E
failure of both the InfiniBand leaf switches and the Ethernet switch
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Correct answersB, E
ExplanationExplanation:
Ethernet switch for administrative connectivity to servers in the Database Machine Connect any combination of up to 18 Exadata Database Machine racks or Exadata Storage Expansion Racks via the InfiniBand fabric. Larger Configurations can be built with external InfiniBand switches.
Connected racks can be any combination of v2, X2, X3 or X4 generation hardware. References:
https://www.oracle.com/technetwork/database/exadata/exadata-storage-expansion-x5-2-ds-
2406252. pdf
Question 3
Multiple choice
Which two statements are true about RMAN incremental level-1 backups for a database running on an X5 Database Machine?
-
A
Block Change tracking (BCT) is not needed for databases in an X5 Database Machine, because ASM automatically does block change tracking when diskgroups are built from griddisks.
-
B
cellsrv filters blocks and returns only those that have changed since the last backup, for databases in archivelogmode.
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C
cellsrv returns all blocks that have been or might have been changed since the last backup, and RMAN filters the blocks that do not require backup.
-
D
cellsrv filters blocks and returns only those that have changed since the last backup, for databases in noarchivelogmode.
-
E
Block Change Tracking (BCT) is not needed for databases in an X5 Database Machine, because change tracking is done by cellsrv.
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Correct answersD, E
ExplanationExplanation:
D: Whenever data blocks change, the Change Tracking Writer (CTWR) background process tracks the changed blocks in a private area of memory. When RMAN performs an incremental backup on the Exadata platform, cellsrv filters out unwanted blocks and sends back only those that have changed since the last level 0 or level 1 backup. E: For the Exadata platform, you may choose to allow cellserv to do all the blocking filtering for incremental backups. Note: RMAN block change tracking is used to improve the performance of incremental backup. The level 0 incremental backup scans the entire database but level 1 incremental backups use the block change tracking file to scan only the blocks that have changed since the last backup. This significantly reduces the amount of reads that are required on the database. References:
Expert Oracle Exadata (29 Aug 2015), page 319
You plan to monitor the status of the motherboard, memory, power, fans, and network cards on the database nodes in your Exadata X6 Database Machine using Enterprise Manager. Where must you set the thresholds for these hardware components and why, to assure that sensor readings, faults, and any related alerts, are visible in Enterprise Manager?
-
A
No thresholds need to be set because they are present in the ILOM and in Enterprise Manager.
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B
Set thresholds in ILOM and in Enterprise Manager because they are not present anywhere and must be set in both places.
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C
Set thresholds only in ILOM because they are not preset anywhere but need to be set only in ILOM.
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D
No thresholds need to be set because they are preset in the ILOM and these are sufficient for monitoring.
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Question 5
Multiple choice
Identify the four software components that run only on an Exadata Database Machine Database Server.
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A
-
B
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C
-
D
Oracle Enterprise Manager Agent (OMA)
-
E
Automatic Diagnostic Repository Command Interpreter (ADRCI)
-
F
-
G
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Correct answersA, C, D, F
ExplanationReferences:
https://docs.oracle.com/en/engineered-systems/exadata-database-machine/sagug/exadata-storage-server-software-introduction.html#GUID-8B06314E-9CD4-4D69-A128-214829AEE4D5
A file contains a script with several EXACLI commands that must be executed on each cell in an X5 full rack. The script must run on each cell simultaneously. How would you achieve this?
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A
Copy the script to all cells using the DCLI command and manually execute it on each cell using the DCLI command.
-
B
Copy the script to the cells using the EXACLI command and execute the script on all cells using the EXACLI command.
-
C
Execute it on all cells using the EXADCLI command specifying the file name containing the EXACLI script.
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D
Copy the script to all cells using the CELLCLI command and execute it on all cells in parallel using the CELLCLI command.
-
E
Execute it on all cells using the DBMCLI command specifying the file name containing the EXACLI script.
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Correct answerC
ExplanationExplanation:
The exadcli utility runs commands on multiple remote nodes in parallel threads. You can issue an ExaCLI command to be run on multiple remote nodes. Remote nodes are referenced by their host name or IP address. Unlike dcli, exadcli can only execute ExaCLI commands. Other commands, for example, shell commands, cannot be executed using exadcli. References:
http://docs.oracle.com/cd/E80920_01/DBMMN/exadcli.htm#DBMMN-GUID-4AE469A6-F291-4737-B975-F1B4B91D0BA0
Question 7
Multiple choice
Which two statements are true about backup performance when using Recovery Manager (RMAN) on an X5 Database Machine?
-
A
Backups are fast because the Infiniband network is faster than fiber channel storage, so RMAN read I/
O operations are faster than in traditional storage networks.
-
B
Backups are fast, because physical I/Os operations are reduced by the use of the Storage Index by cellsrv.
-
C
Backups are fast, because data blocks are read from the Database Flash Cache.
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D
Backups are fast, because all data blocks are read from the Exadata Smart Flash Cache.
-
E
For incremental backups using Block Change Tracking, cellsrv filters blocks and returns only those that have changed since the last backup.
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Correct answersD, E
ExplanationExplanation:
D: The storage server software manages the flash cache and can recognize different types of I/O requests so that non-repeatable data access like RMAN backup I/O does not flush database blocks from the cache.
It also prioritizes frequently accessed block types such as redo logs, control files, and index root blocks. E: RMAN block change tracking allows incremental backups to run very quickly and efficiently. With block change tracking, only the areas of the database that have been modified since the last incremental backup or full backup are read from disk. Incorrect Answers:
C: Database Flash Cache is separate from Exadata Smart Flash Cache. The Database Smart Flash Cache feature and increase the buffercache of your database from like 100G or 200G to 300-700G on that same server. References:
https://logicalread.com/using-oracle-exadata-flash-cache-mc05/#.Wd80zmiCyUk
http://www.oracle.com/technetwork/database/availability/maa-tech-wp-sundbm-backup-11202-183503.pdf
Question 8
Multiple choice
Your X6 Exadata Database Machine is running Oracle Database 12c, and has a large database with some
very large tables supporting OLTP workloads. High-volume insert applications and high-volume update workloads access the same tables. You wish to compress these tables without causing unacceptable performance overheads to the OLTP workload. Which three are true regarding this requirement?
-
A
Compression is performed on database servers when using row store compress advanced in an Exadata environment.
-
B
Using row store compress advanced will compress the data more than if using column store compress for archive low.
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C
The compression method column store compress for archive high is the worst fit for this requirement.
-
D
Compression is performed on Exadata Storage Servers when using row store compress advanced in an Exadata environment.
-
E
Using row store compress advanced will compress the data less than if using column store compress for query low.
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Correct answersA, B, D
ExplanationExplanation:
A: Creating a Table with Advanced Row Compression
The following example enables advanced row compression on the table orders: CREATE TABLE orders ... ROW STORE COMPRESS ADVANCED; B: ARCHIVE LOW compression (Exadata only), recommended for Archival Data with Load Time as a critical factor Incorrect Answers:
E: QUERY LOW compression (Exadata only), recommended for Data Warehouse with Load Time as a critical factor. References:
https://docs.oracle.com/database/121/ADMIN/tables.htm#ADMIN015
https://uhesse.com/2011/01/21/exadata-part-iii-compression/
Batch and DSS workloads on your Exadata X6 Database Machine are causing performance problems for OLTP workloads at certain times of the day. There are five RAC databases performing OLTP I/O. Two of them also perform batch I/O. There is another RAC database that performs only DSS I/O. You are asked to resolve this problem so that the OLTP workload will not suffer when competing with the batch or DSS workloads. You decide to use the I/O resource manager. Which is the best way to solve this problem?
-
A
Create a category plan with EXADCLI calling EXACLI to give the OLTP category the highest priority on all the cells, and use the Database Resource Manager to create the OLTP category and map all OLTP-oriented consumer groups in all databases to it.
-
B
Use the Database Resource Manager to give the OLTP category the highest priority and use EXADCLI calling EXACLI to create the OLTP category on all the cells.
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C
Create a category plan with EXADCLI calling EXACLI to give the OLTP category the highest priority on all the cells, and use the Database Resource Manager to give the OLTP consumer group the highest priority on all databases.
-
D
Create a database plan using EXADCLI calling EXACLI to give OLTP I/O the highest priority from all six databases.
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Correct answerC
ExplanationExplanation:
You can manage I/O resources based on categories by creating a category plan.
You can add any number of categories, or modify the predefined categories. You should map consumer groups to the appropriate category for all databases that use the same cell storage. Any consumer group without an explicitly specified category defaults to the OTHER category. References:
http://docs.oracle.com/cd/E80920_01/SAGUG/exadata-storage-server-iorm.htm
Question 10
Multiple choice
Which two are true about Smart Scan?
-
A
A query rewrite may occur to a materialized view stored in Exadata, and it will always benefit from Smart Scan.
-
B
Column projection does not contribute to the performance benefit of Smart Scan.
-
C
A query rewrite may occur to a materialized view stored in Exadata but will never benefit from Smart Scan.
-
D
It is possible to offload single row functions to the Exadata Storage Servers.
-
E
Join processing can be partly offloaded to Exadata Storage Servers.
-
F
Join processing can be fully offloaded to Exadata Storage Servers.
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Correct answersD, E
ExplanationExplanation:
D: With Exadata storage, database operations are handled much more efficiently. Queries that perform table scans can be processed within Exadata storage with only the required subset of data returned to the database server. Row filtering, column filtering and some join processing (among other functions) are performed within the Exadata storage cells. When this takes place only the relevant and required data is returned to the database server. E: With Smart Scan processing, row filtering, column filtering, some join processing, and other functions are performed in the Exadata cells. References:
http://www.centroid.com/blog/exadata-smart-scan-processing
Question 11
Multiple choice
As part of planning for database consolidation, you grouped your databases into two categories based on different technical and business objectives. Which three statements are true about possible configurations for your Exadata X6 Database Machine fabric?
-
A
The storage grid may be partitioned when deploying a single-rack Database Machine configuration using virtualization.
-
B
The database grid may be partitioned when deploying a multirack Database Machine configuration.
-
C
A single database cluster benefits from accessing multiple storage grids.
-
D
Multiple database clusters may access the same storage grid.
-
E
Multiple database clusters never benefit from accessing a single storage grid.
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Question 12
Multiple choice
Which two statements are true about Exadata X5 cell metrics and alerts?
-
A
Cell alerts on each storage server are accumulated in memory by the CELLSRV process and stored on a filesystem-based repository.
-
B
Cell metrics are written to disk every hour by default.
-
C
Cell metrics on each storage server are accumulated in memory by the CELLSRV process and written to a filesystem-based repository.
-
D
Cell alerts on each server are accumulated in memory by the MS process and stored on a filesystem- based repository.
-
E
Cell alerts are written to disk every hour by default.
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Correct answersB, D
ExplanationExplanation:
Metrics are a series of measurements that are computed and retained in memory for an interval of time, and stored on a disk for a more permanent history. On the storage servers, the CELLSRV process provides the majority of Oracle Exadata storage services and is the primary storage software component. One of its functions is to process, collect, and store metrics. The Management Server (MS) process receives the metrics data from CELLSRV, keeps a subset of metrics in memory, and writes to an internal disk-based repository hourly. References:
http://www.oracle.com/technetwork/articles/servers-storage-admin/monitor-exadata-em12-
2291964. html
Question 13
Multiple choice
Which two options should be used to identify a damaged or failing flash card on an X6 Database Machine high-capacity storage server?
-
A
Using the CELLCLI CALIBRATE command on the storage server after logging in as the root user
-
B
Using the CELLCLI LIST LUN DETAIL command as the celladmin user
-
C
Using the CELLCLI CALIBRATE command on the storage server after logging in as the celladmin user
-
D
Hardware monitoring using the storage server ILOM
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Correct answersA, D
ExplanationExplanation:
The CALIBRATE command runs raw performance tests on cell disks, enabling you to verify the disk performance before the cell is put online. You must be logged on to the cell as the root user to run CALIBRATE.
Oracle ILOM automatically detects system hardware faults and environmental conditions on the server. If a problem occurs on the server, Oracle ILOM will automatically do the following: Illuminate the Service Required status indicator (LED) on the server front and back panels.
Identify the faulted component in the Open Problems table. Record system information about the faulted component or condition in the event log. References:
http://docs.oracle.com/cd/E80920_01/SAGUG/exadata-storage-server-cellcli.htm#SAGUG20617
Question 14
Multiple choice
Which two Exadata X5 security features would you configure to control which databases can access which griddisks, when multiple databases share space on your storage servers in an unpartitioned storage grid?
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A
Using EXADCLI instead of CELLCLI to create the griddisks
-
B
Exadata storage realms using database-scoped security mode
-
C
file permissions on the griddisks in each storage server
-
D
file permissions on the griddisks in each database server
-
E
Exadata storage realms using ASM-scoped security mode
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Correct answersB, E
ExplanationReferences:
https://docs.oracle.com/en/engineered-systems/exadata-database-machine/dbmsq/exadata-security-features.html#GUID-F53D9493-5927-4106-8D86-65D759419E46
https://docs.oracle.com/en/engineered-systems/exadata-database-machine/dbmsq/security-guide-exadata-database-machine.pdf
Question 15
Multiple choice
Which three storage components are available after nonvirtualized standard deployment of an X5 Database Machine using high-capacity disks?
-
A
mirrored system area on hard disk 0, hard disk 1, and hard disk 2
-
B
Exadata Smart Flash Cache using all of the flashdisk space
-
C
the DBFS_DG diskgroup with high redundancy
-
D
mirrored system area on hard disk 0 and hard disk 1
-
E
the RECO_<DBM_Name> ASM diskgroup
-
F
the DATA_<DBM_Name> ASM diskgroup
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Correct answersC, E, F
ExplanationExplanation:
The first two disks of Exadata Storage Server are system disks. Oracle Exadata Storage Server Software system software resides on a portion of each of the system disks. These portions on both system disks are referred to as the system area. The default configuration on Exadata is to have 3 diskgroups - DATA, RECO, and DBFS_DG.
Question 16
Multiple choice
Which two are true concerning Columnar Flash Caching?
-
A
It can be enabled or disabled for individual databases by using I/O Resource Manager database plans.
-
B
It automatically transforms ROW STORE COMPRESS compressed data into a pure columnar format
during Exadata Smart Flash Cache population.
-
C
Data is either cached in Hybrid Columnar Compressed format or in pure compressed format, but never in both formats at the same time.
-
D
It is enabled by default.
-
E
It automatically transforms Hybrid Columnar Compressed (HCC) data into a pure columnar format
during Exadata Smart Flash Cache population.
-
F
It improves single-row lookup performance.
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Correct answersD, E
ExplanationExplanation:
D: In-Memory Columnar Caching on cells is enabled by default when the INMEMORY_SIZE is configured.
You do not need to do anything to get this enhancement. E: Columnar Flash Caching implements a dual format architecture in Exadata flash by automatically transforming frequently scanned Hybrid Columnar Compressed data into a pure columnar format as it is loaded into the flash cache. Incorrect Answers:
F: Columnar Flash Caching accelerates reporting and analytic queries while maintaining excellent performance for OLTP style single row lookups. References:
http://docs.oracle.com/cd/E80920_01/SAGUG/exadata-storage-server-monitoring.htm#SAGUG20883
http://www.oracle.com/technetwork/database/exadata/exadata-x5-8-ds-2745934.pdf
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