Certified Oracle 1Z0-027 Practice Exam Online

NEW QUESTION 1
You plan to migrate your Oracle Version 11.1.0.2 database to your Exadata Database Machine.
The database supports an online transaction processing (OLTP) workload and is currently hosted on a Little Endian platform
Which two are the supported and appropriate migration methods to minimize downtime?

• A. Upgrade source database to 11.2.0 and migrate using a physical standby database.
• B. Migrate using Data Pump.
• C. Migrate using GoldenGate.
• D. Migrate using cross platform Transportable Database.
• E. Migrate using ASM online migration.

Answer: AB

Explanation:
Reference: Migrating the Oracle E-Business Suite Database to Oracle Exadata Database Machine Using Transportable Tablespaces
Reference: Migrating Oracle E-Business Suite to Oracle Exadata Database Machine Using Oracle Data Pump

NEW QUESTION 2
Your database Machine has the exachk utility pre-installed and you decide to use it periodically, to validate the installation against Oracle’s recommended best practices.
Which two actions could you take to do this?

• A. Use a cron job on a database node to run it at regular intervals.
• B. Rut it once from a database node and it will then perform periodic monitoring automatically.
• C. Use a cron job on each cell to run it at regular intervals.
• D. Run it once on each cell and it will then perform periodic monitoring automatically.
• E. Create a Job in Enterprise Manager to run the exachk utility at regular intervals.

Answer: AE

NEW QUESTION 3
Which two are true about Smart Scan?

• A. a query rewrite may occur to a container table stored in Exadata but will never benefit From Smart scan.
• B. Column projection does not contribute to the performance benefit of Smart Scan
• C. It is possible to offload single row functions to the storage servers.
• D. Some joins can be offloaded to the storage servers.
• E. A query rewrite may occur to a container table stored Exadata, and it will always benefit from Smart Scan.
• F. All joins can be offloaded to the storage servers.

Answer: CD

Explanation:
C: 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.
D (not F):
* Exadata performs joins between large tables and small lookup tables, a very common scenario for data warehouses with star schemas. Joining large tables and small lookup tables is implemented using Bloom Filters, which are a very efficient probabilistic method to determine whether a row is a member of the desired result set.
* If storage indexes are so great, why doesn’t Oracle Exadata use them all the time? The short answer is that they are created and used only when they will be beneficial.
* To use storage indexes, Oracle Exadata queries must use smart scans, so not all types of applications can benefit from storage indexes. Applications with queries that include predicates and perform a lot of full table scans or fast full scans of indexes—typically those used in data warehousing environments—will benefit greatly from storage indexes. Online
* transaction processing (OLTP) applications, on the other hand, typically access a small number of rows through standard indexes and do not perform full table scans, so they may not benefit from storage indexes.
Note:
* Storage indexes reside in the memory of the storage servers—also called storage cells—and significantly reduce unnecessary I/O by excluding irrelevant database blocks in the storage cells.
* To use storage indexes, Oracle Exadata queries must use smart scans, so not all types of applications can benefit from storage indexes.
Incorrect:
Not B: Exadata provides column filtering, also called column projection, for table scans. Only the columns requested are returned to the database server rather than all columns in a table. For example, when the following SQL is issued, only the employee_name and employee_number columns are returned from Exadata to the database kernel.
SELECT employee_name, employee_number FROM employee_table.
For tables with many columns, or columns containing LOBs (Large Objects), the I/O bandwidth saved can be very large. Using both predicate and column filtering dramatically improves performance and reduces I/O bandwidth consumption. In addition, column filtering also applies to indexes, allowing for even faster query performance.
Reference: Oracle Communications Data Model Implementation and Operations Guide, Exadata Smart Scan Processing and Storage Index

NEW QUESTION 4
Which three are among the software components that constitute the QoS Management framework?

• A. Cluster Health Monitor (CHM)
• B. Cluster Verification Utility (CLUVFY)
• C. O/S Resource Manager
• D. Grid Infrastructure for a standalone server
• E. Grid Infrastructure for a cluster
• F. OC4J cluster resource

Answer: AEF

Explanation:
A: In conjunction with Cluster Health Monitor, QoS Management’s Memory Guard detects nodes that are at risk of failure due to
memory over-commitment. It responds by automatically preventing new connections thus preserving existing workloads and restores connectivity once the sufficient memory is again available.
F: The ora.oc4j is for the QoS (Quality of Service Management), which is only available on
Exadata.
Incorrect:
Not B: The Cluster Verification Utility (CVU) performs system checks in preparation for installation, patch updates, or other system changes. Using CVU ensures that you have completed the required system configuration and preinstallation steps so that your Oracle grid infrastructure or Oracle Real Application Clusters (Oracle RAC) installation, update, or patch operation completes successfully.

NEW QUESTION 5
To troubleshoot a possible hardware problem, you consider moving all disk drives from one Exadata storage server to a replacement chassis.
You must contain storage availability while performing task.
The Exadata storage server is an X3-8 Database Machine and storage grid is not
partitioned.
Which two factors would prevent you from moving the disks from one Exadata storage server to another one?

• A. The existence of an external redundancy ASM diskgroup
• B. The existence of a normal redundancy ASM diskgroup
• C. The existence of an ASM diskgroup with the repair_time attribute set to 0.
• D. The existence of an ASM diskgroup with its compatible.asm attribute set to 10.2.0.0.0
• E. Offline or inactive celldisks in another Exadata server

Answer: AD

Explanation:
A: If you want Oracle ASM to mirror files, specify the redundancy level as NORMAL REDUNDANCY (2-way mirroring by default for most file types) or HIGH REDUNDANCY (3-way mirroring for all files). You specify EXTERNAL REDUNDANCY if you do not want mirroring by Oracle ASM. For example, you might choose EXTERNAL REDUNDANCY if you want to use storage array protection features.
D: Restoring the redundancy of an Oracle ASM disk group after a transient disk path failure can be time consuming. This is especially true if the recovery process requires rebuilding an entire Oracle ASM failure group. Oracle ASM fast mirror resync significantly reduces the time to resynchronize a failed disk in such situations. When you replace the failed disk, Oracle ASM can quickly resynchronize the Oracle ASM disk extents.
To use this feature, the disk group compatibility attributes must be set to 11.1 or higher.
Incorrect:
Not C: You can set the DISK_REPAIR_TIME disk group attribute to delay the drop operation by specifying a time interval to repair the disk and bring it back online.
Note:
* The redundancy levels are:
/ External redundancy
Oracle ASM does not provide mirroring redundancy and relies on the storage system to provide RAID functionality. Any write error cause a forced dismount of the disk group. All disks must be located to successfully mount the disk group.
/ Normal redundancy
Oracle ASM provides two-way mirroring by default, which means that all files are mirrored so that there are two copies of every extent. A loss of one Oracle ASM disk is tolerated. You can optionally choose three-way or unprotected mirroring.
/ High redundancy
Oracle ASM provides triple mirroring by default. A loss of two Oracle ASM disks in different failure groups is tolerated.
Reference: Administering Oracle ASM Disk Groups

NEW QUESTION 6
Which two are true concerning the allocation of I/O resources by the IORM within the CELLSRV process?

• A. If two consumer groups A and B in the PROD database get 10% and 15% respectively of resource allocation, then the percentage of I/O resource would be the same if they got 20% and 30% respectively, provided that the category plans and inter database plans are unchanged, and consumer groups A and B are still mapped to the same category.
• B. If two consumer groups C and D In the PROD database get 10% and 15% respectively of resource allocation, then the percentage of I/O resource would be the same if they still got 10% and 15% respectively and were remapped to a different category by the DBA, provided that the category plans and Interdatabase plans are unchanged.
• C. If two consumer groups P and Q In the PROD database get 20% and 10% respectively of resource allocation, then the percentage of I/O resource would be the same if they got 10% and 5% respectively, and the Interdatabase plan has changed, provided that the category plan is unchanged, and consumer groups A and B are still mapped to the same categories.
• D. Log Writer I/O and Control File I/O are high priority I/O managed automatically by IORM.
• E. Database Writer I/O is considered to be the highest priority I/O and is managed based on attributes of the IORM plan.

Answer: CD

Explanation:
*(not A, Not B) Rules in an interdatabase resource plan specify allocations to databases, not consumer groups.
* IORM Rules
IORM is only "engaged" when needed.
/ (D) Redo and control file writes always take precedence.
/ (Not E) DBWR (database writer) writes are scheduled at the same priority as user IO.
/ IORM does not intervene if there is only one active consumer group on one database.
/ Any disk allocation that is not fully utilized is made available to other workloads in relation to the configured resource plans.
/ Background IO is scheduled based on their priority relative to user IO.
/ For each cell disk, each database accessing the cell has one IO queue per consumer group and three background queues
Note:
* Use IORM metrics to track
/ I/O load per Consumer Group (IOPS, MBPS, disk utilization %)
/ I/O throttling per Consumer Group Reference: Using IORM with Exadata

NEW QUESTION 7
You are checking the status of the ports on the one of the InfiniBand switches in your Database Machine.
You have run the getportstatus as shown:

You have 36 ports to check.
Which two methods would you use to check the status of all 36 ports?

• A. Use Enterprise Manager.
• B. Use the ibqueryerros.pl script logged into the InfiniBand switch as root.
• C. Use Database Control.
• D. Create user-defined metrics for the InfiniBand switch.

Answer: AB

Explanation:
http://docs.oracle.com/cd/E17559_01/install.111/e20085/e20085-03.htm

NEW QUESTION 8
You are using Hybrid Columnar Compression for a table stored in a tablespace that is contained in an Exadata-based ASM diskgroup. Identify three statements that correctly explain where the compression and decompression can be done.

• A. Decompression can be done on the database servers.
• B. Compression can be done on the Exadata storage servers.
• C. Compression can be done on the database servers.
• D. Decompression can be done on the Exadata storage servers.

Answer: ACD

Explanation:
* decompression
/ Queries run directly on Hybrid Columnar Compressed data does not require the data to be decompressed
/ Data that is required to satisfy a query predicate does not need to be decompressed; only the columns and rows being returned to the client are decompressed in memory
/ The decompression process typically takes place on the Oracle Exadata Storage Server in order to maximize performance and
offload processing from the database server.

NEW QUESTION 9
You recently upgraded your Exadata image to the latest release; previously you were using 11.2.0.3.
At the same time, you decide to address some performance problems as follows:
You noticed increased latency for the database log writer, especially during the quarterly battery learn cycle on the cells.
You have complaints of erratic performance from certain write-intensive applications. Which two actions could improve performance in these areas?

• A. Enable write-back flashcache by setting lunWriteCacheMode to Write Back Mode.
• B. Use ALTER TABLE in the database to set CELL_FLASH_CACHE = KEEP for the tables belonging to the affected application.
• C. Configure Smart Flash Log on the cells to use some of these of the space on the cell flash devices.
• D. Configure the table belonging to the affected application using CELLCLI, to the set CELL_FLASH_CACHE = KEEP.
• E. Configure Smart Flash Log on the database server to use server flash memory.

Answer: BC

Explanation:
B: The following command could be used to pin the table CUSTOMERS in Exadata
Smart Flash Cache
ALTER TABLE customers STORAGE (CELL_FLASH_CACHE KEEP)
C: Creating Flash Disks Out Of The Flash Cache
When an Exadata cell is installed, by default, all the flash is assigned to be used as flash cache and
user data is automatically cached using the default caching behavior. Optionally, a portion of the
cache can be reserved and used as logical flash disks. These flash disks are treated like any
Exadata cell disk in the Exadata cell except they actually reside and are stored as non- volatile
disks in the cache.
Note:
* Pinning Objects In The Flash Cache
Preferential treatment over which database objects are cached is also provided with the Exadata
Smart Flash Cache. For example, objects can be pinned in the cache and always be cached, or an
object can be identified as one which should never be cached. This control is provided by the
new storage clause attribute, CELL_FLASH_CACHE, which can be assigned to a database table, index, partition and LOB column
* There are two techniques provided to manually use and manage the cache. The first enables the
pinning of objects in the flash cache. The second supports the creation of logical disks out of the
flash for the permanent placement of objects on flash disks.

NEW QUESTION 10
Which three are true abort Enterprise Manager plug- in configuration for the Database Machine?

• A. There are several separate plug-ins for Grid Control.
• B. There is one plug-in for Cloud Control.
• C. There are several separate plug-ins for Cloud Control.
• D. Some plug-ins require SNMP trap forwarders.
• E. All plug-ins require SNMP trap forwarders.
• F. There is one plug-in for Grid Control.

Answer: ACD

NEW QUESTION 11
You have altered an index supporting a constraint to be invisible on a large read only data warehouse table, to determine it Smart Scan operations will be fast enough to satisfy your performance requirements.
Given the results of your testing, you consider dropping the index.
Which two statements are true?

• A. You must retain the index and set the constraint to DISABLE NOVALIDATE RELY to enforce the constraint
• B. You may drop the index and use a constraint with the DISABLE NOVALIDATE RELY flags
• C. You must retain the index and make it visible again for the constraint to be enforced.
• D. You may drop the index and make the constraint invisible, because this is enough for the constraint to be enforced.
• E. You may retain the index, and leave it as invisible, because this is enough for the constraint to be recognized.

Answer: AC

Explanation:
Note:
* You may have noticed that we introduced Invisible Indexes as an 11g New Feature. Their main benefit is that we can test whether performance differs if we would drop an index without actually dropping it. This is particular useful after an Exadata Migration because we expect that some conventional indexes migrated are now obsolete and may be substituted by Storage Indexes.
* With making indexes invisible, we can easily check whether indexes are useful without having to drop (and in case recreate) them actually. While this may be of interest for “ordinary” Oracle Databases already, it is particular a useful feature for Exadata where we expect some conventional indexes to become obsolete after a migration.
* DISABLE NOVALIDATE RELY means: "I don't want an index and constaraint checking to slow down my batch data loading into datawarehouse, but the optimizer can RELY on my data loading routine and assume this constraint is enforced by other mechanism". This information can greatly help optimizer to use correct materialized view when rewriting queries. So if you don't use materialized views for query rewrite then you can put RELY for all your constraints (or NORELY for all your constraits) and forget about it.

NEW QUESTION 12
Which two statements are true about the use of direct path loads when selecting from external tables in a database on a Database Machine?

• A. INSERT INTO . . . SELECT FROM statements, executed serially, which select from external tables, require the APPEND hint to use direct path loading.
• B. CREATE TABLE . . . AS SELECT statements, which select from external tables, attempt to use in direct path loading automatically.
• C. CREATE TABLE . . . AS SELECT statements, which select from external tables, require the APPEND hint to use direct path loading.
• D. INSERT INTO . . . SELECT FROM statements, executed serially, which select from external tables, are unable to use direct path loading.

Answer: AB

Explanation:
A CTAS (Create table as select) will always use direct path (B, not C) load but IAS (Insert as select) statement will not. In order to achieve direct path load with an IAS statement you must add the APPEND hint to the command (A, not D).
Direct path loads can also run in parallel. You can set the parallel degree for a direct path load
either by adding the PARALLEL hint to the CTAS or IAS statement or by setting the
PARALLEL clause on both the external table and the table into which the data will be loaded.
Once the parallel degree has been set at CTAS will automatically do direct path load in parallel
but an IAS will not. In order to enable an IAS to do direct path load in parallel you must alter the session to enable parallel DML.
Note:
* Parallel Direct Path Load
The key to good load performance is to use direct path loads wherever possible. A direct path
load parses the input data according to the description given in the external table definition,
converts the data for each input field to its corresponding Oracle data type, then builds a column
array structure for the data. These column array structures are used to format Oracle data blocks
and build index keys. The newly formatted database blocks are then written directly to the database, bypassing the standard SQL processing engine and the database buffer cache.
Reference: Best Practices for Implementing a Data Warehouse on the Oracle Exadata Database Machine; Using CTAS & Exchange Partition Replace IAS for Copying Partition on Exadata

NEW QUESTION 13
Which two are true about the use of DBFS in a Database Machine environment?

• A. DBFS must be used to bulk load data into a database on the Database Machine if the staging area requires Exadata based shared storage.
• B. DBFS must be used to have a POSIX compliant shared storage solution that is accessible from the database servers on a Database Machine.
• C. DBFS must be used to bulk load data into a production database on the Database Machine.
• D. DBFS must use the DBFS_DG diskgroup for any DBFS store.
• E. DBFS must be used to have a POSIX-compliant Exadata-based shared storage solution.

Answer: CD

NEW QUESTION 14
Which two are true about the use of the Integrated Lights Out Manager (ILOM) on the Database Machine?

• A. ILOM can be used to power-on the Cisco switch.
• B. ILOM can be used to power on the InfiniBand switches.
• C. ILOM can be used to power-on the database servers.
• D. ILOM generates hardware alerts for the power distribution units.
• E. ILOM provides a remote console for the storage servers.

Answer: CE

Explanation:
* The Oracle ILOM Remote Console is supported on all Oracle Sun x86 processor-based servers. It is also supported on some SPARC processor-based servers. The Oracle ILOM Remote Console is a Java application that you can launch from the Oracle ILOM web interface
* Remote Management: Integrated Lights Out Manager (ILOM) Ethernet port

NEW QUESTION 15
Which two activities are supported on the storage servers in the Database Machine?

• A. Installing an alternative package manager
• B. configuring secure shell user equivalency for the callmonitor user
• C. changing root password
• D. upgrading the Storage Server software package using RPN
• E. upgrading a device driver for hard disks when inserting a replacement disk after a hard disk failure

Answer: BC

NEW QUESTION 16
You plan to monitor storage servers after configuring an I/O resource manager plan with directives for inter-database plans and intra-database plans.
Which two types if metrics would help assess the impact of the intra-database plans on I/O to the storage servers?

• A. Category I/O
• B. Database I/O
• C. Resource Consumer Group I/O
• D. Smart Flash Log I/O
• E. Smart Flash Cache I/O

Answer: BC

Explanation:
B: Database metrics provide information about the size of the I/O load from each database specified in the interdatabase plan.
C: Consumer group metrics provide information about the size of the I/O load from each consumer group specified in a database resource plan. Each database in the interdatabase plan has metrics for each of its consumer groups.
Note:
* I/O Resource Manager (IROM) Settings
* Incorrect:
Not A: Category metrics provide information about the size of the I/O load from each category specified in the current IORM category plan.

NEW QUESTION 17
Which two are regarding the case of storage indexes?

• A. To increase the chance of using the a storage index, you can make table indexes invisible.
• B. To maximize the benefit of storage Indexes, load your data stored on the filtered columns.
• C. The cell physical 10 bytes saved by storage index statistic returns multiple rows, one for each storage server.
• D. Storage indexes are retained after a cell is rebooted.
• E. Avoid the use of bind variables because Storage Indexes do not work with bind variables.

Answer: AB

Explanation:
To use storage indexes, Oracle Exadata queries must use smart scans, so not all types of applications can benefit from storage indexes.
* 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.

NEW QUESTION 18
Which two are true concerning the allocation of I/O resources by the IORM within the CELLSRV process?

• A. Control File I/O is managed automatically at high priority by IORM.
• B. Control File I/O is considered part of the SYSTEM resource Consume group by IORM.
• C. Log Writer I/O to the Smart Flash Log is considered part of the SYSTEM resource consumer group by IORM.
• D. Log Writer I/O to the Smart Flash Log is managed automatically at high priority by IORM.
• E. Database Writer I/O is managed automatically at normal priority by IORM.
• F. Database Writer I/O is considered part of the SYSTEM resource consumer group by IORM.

Answer: AE

Explanation:
Note:
* IORM Rules
IORM is only "engaged" when needed.
/ (A) Redo and control file writes always take precedence.
/ (E) DBWR (database writer) writes are scheduled at the same priority as user IO.
/ IORM does not intervene if there is only one active consumer group on one database.
/ Any disk allocation that is not fully utilized is made available to other workloads in relation to the configured resource plans.
/ Background IO is scheduled based on their priority relative to user IO.
/ For each cell disk, each database accessing the cell has one IO queue per consumer group and three background queues.
/ Background IO queues are mapped to "high", "medium", and "low" priority requests with different IO types mapped to each queue.
/ If no intradatabase plan is set, all non-background IO requests are grouped into a single consumer group called OTHER_GROUPS.
Reference: Using IORM with Exadata

NEW QUESTION 19
To guarantee proper cooling, you plan to place perforated floor tiles near your Database Machine.
Where, in relation to the cabinet, should they be placed?

• A. On the left side, because the air flow is from left to right
• B. At the back, because the air flow is from back to front
• C. On the right side, because the air flow is from right to left.
• D. At the front, because the air flow is from front to back
• E. Underneath the cabinet, because the air flow is from bottom to top

Answer: D

Explanation:
Airflow must be front-to-back.
Reference: Oracle White Paper, ORACLE Exadata Database Machine X3-8

NEW QUESTION 20
Consider the following sequence of CELLCLI commands and SQL statements:

All CELLCLI commands and SQL statements are executed successfully without warnings. Which statement is true about the I/O performance of the DATA01 ASM diskgroups?

• A. The DATA01 diskgroups has better performance because the DATA01 griddisks were created first.
• B. The DATA02 ASM diskgroup has better performance because the DATA02 diskgroups was created first.
• C. The DATA01 diskgroup has better performance because the DATA01 griddisks are created on interleaved cell disks.
• D. The performance of both diskgroups is balanced because they are created on interleaved griddisks.

Answer: A

Explanation:
Griddisks are the fourth layer of abstraction, and they will be the Candidate Disks to build your ASM diskgroups from. By default (interleaving=none on the Celldisk layer), the first Griddisk that is created upon a Celldisk is placed on the outer sectors of the underlying Harddisk. It will have the best performance therefore
Incorrect:
Not D: non-interleaved is the default.

NEW QUESTION 21
You have a partitioned database grid on an X3-2 full rack with two four-node RAC clusters called CLUSA and CLUSB. The storage grid, however, has not been partitioned.
Which files on which servers must be modified after connecting an Exadata storage full expansion rack to your X3-2 Exadata Database Machine on the InfiniBand network so that the cells on the expansion rack are added to the storage grid?

• A. The CELLINIT.ORA files on database servers in CLUSA
• B. The CELLIP.ORA files on the database servers in CLUSA
• C. The CELLINIT.ORA files on the database servers in CLUSB
• D. The CELLIP.ORA files on all existing and newly added Exadata storage servers.
• E. The CELLIP.ORA files on the database servers in CLUSB

Answer: BE

Explanation:
Note:
* cellinit.ora, cellip.ora
-- on database server
cellinit.ora - identifies the storage network interface on the database server cat /etc/oracle/cell/network-config/cellinit.ora
cellip.ora - identifies the Exadata cells that are accessible to the database server cat /etc/oracle/cell/network-config/cellip.ora
* The cellip.ora is the configuration file, on every compute node, that tells ASM instances which cells are available to this cluster.
Here is a content of a typical cellip.ora file for a quarter rack system:
$ cat /etc/oracle/cell/network-config/cellip.ora cell="192.168.10.3"
cell="192.168.10.4" cell="192.168.10.5"

NEW QUESTION 22
You are in the planning stage of the network configuration for your Database Machine. The requirements are:
1. A fault-tolerant network, providing higher availability for connections to database instances
2. Fault tolerance providing higher availability for connections to perform management functions on the database and storage servers.
3. Full monitoring of all Database Machine components using Enterprise Manager
Which three components require external Ethernet network cables to connect your existing network infrastructure to your database machine to satisfy this requirement?

• A. Database servers
• B. Exadata storage servers
• C. InfiniBand storage servers.
• D. Power distribution units (PDUs)
• E. Cisco Ethernet switch

Answer: ADE

NEW QUESTION 23
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