Oracle 1Z0-027 Online Practice Questions and Exam Preparation

Oracle 1Z0-027 Online Questions & Answers

• Question 31:

  Identify the three components that serve a purpose only in the Database Machine.

  A. ASM intelligent Data Placement (IDP)
  B. Intelligent Database Protocol (IDB)
  C. Database Resource Manager (DBRM)
  D. I/O Resource Manager (IORM)
  E. Database Filesystem (DBFS)
  F. The DISKMON process
  A. ASM intelligent Data Placement (IDP)
  B. Intelligent Database Protocol (IDB)
  D. I/O Resource Manager (IORM)

  ---

  A:Intelligent Data Placement, a feature of ASM that allows placing data in such a way that more frequently accessed data is located close to the periphery of the disk where the access is faster.

  B:The Exadata software is optimally divided between the database servers and Exadata cells. The database servers and Exadata Storage Server Software communicate using the iDB ? the Intelligent Database protocol. iDB is implemented in the database kernel and transparently maps database operations to Exadata-enhanced operations. iDB implements a function shipping architecture in addition to the traditional data block shipping provided by the database. iDB is used to ship SQL operations down to the Exadata cells for execution and to return query result sets to the database kernel. Instead of returning database blocks, Exadata cells return only the

  D:The inter-database I/O allocations are defined within the software in the Exadata cell and managed by the I/O Resource Manager (IORM). The Exadata cell software ensures that inter-database I/O resources are managed and properly allocated within, and between, databases.

• Question 32:

  Your Database Machine 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 decide to compress these tables without causing unacceptable performance overheads to the OLTP application.

  Which three are true regarding this requirement?

  A. Using'compress for oltp'will compress the data less than if using Hybrid Columnar Compression when specified with compress for query low.
  B. The compression is performed on the storage servers when using compress for oltp in an Exadata environment.
  C. The compression method compress for archive high is the worst fit for this requirement.
  D. Using'compress for oltp'will compress the data more than if using Hybrid Columnar Compression when specified with compress for archive low.
  E. The compression is performed on the database servers when using'compress for oltp'in an Exadata environment.
  A. Using'compress for oltp'will compress the data less than if using Hybrid Columnar Compression when specified with compress for query low.
  C. The compression method compress for archive high is the worst fit for this requirement.
  E. The compression is performed on the database servers when using'compress for oltp'in an Exadata environment.

  ---

  Note:

  (E not B):

  *Types of compression

  Basic compression

  OLTP compression

  Warehouse compression

  Online archival compressio

  *

  /OLTP compression allows compression during DML operations. /Basic compression works at the data block level.

  *When you enable table compression by specifying COMPRESS FOR OLTP, you enable OLTP table compression. Oracle Database compresses data during all DML operations on the table. This form of compression is recommended for

  OLTP environments.

  * When you specify COMPRESS FOR QUERY or COMPRESS FOR ARCHIVE, you enable hybrid columnar compression. With hybrid columnar compression, data can be compressed during bulk load operations. During the load process, data is transformed into a column-oriented format and then compressed. Oracle Database uses a compression algorithm appropriate for the level you specify. In general, the higher the level, the greater the compression ratio.

  Hybrid columnar compression can result in higher compression ratios, at a greater CPU cost. Therefore, this form of compression is recommended for data that is not frequently updated.

• Question 33:

  You are planningthe physical installation of two full rack Database Machines and two full- rack expansion racks. The four racks will be combined into one multi rack system.

  Which are the two guidelines for installing this configuration in your data Center?

  A. All Database Machines must be placed side by side with no space between them.
  B. All Expansion Racks must be placed side by side with no space between them.
  C. All racks must be placed in such away that the exhaust air of one rack does not enter theairinlet of another
  D. All racks must be placed side by side with no space between them.
  E. All racks must be isolated from each other with at least one meter between them.
  F. Racks may be placed as required in the machine room.
  G. Expansion Racks must be placed side by side at least one meter apart.
  A. All Database Machines must be placed side by side with no space between them.
  C. All racks must be placed in such away that the exhaust air of one rack does not enter theairinlet of another

  ---

  A:Group related racks together ?for example, racks that run acommon database or are part of a common cluster C:Inadequate cold air flow could result inhigher air inlet temperatures in theservers due to exhaust air recirculation

• Question 34:

  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.
  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.

  ---

  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.

• Question 35:

  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.
  C. It is possible to offload single row functions to the storage servers.
  D. Some joins can be offloaded to the storage servers.

  ---

  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 transactionprocessing (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: OracleCommunications Data Model Implementation and Operations Guide,Exadata Smart Scan Processing and Storage Index

• Question 36:

  You have altered an index supporting a constraint to be invisible onalarge 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 RELYflags
  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.
  A. You must retain the index and set the constraint to DISABLE NOVALIDATE RELY to enforce the constraint
  C. You must retain the index and make it visible again for the constraint to be enforced.

  ---

  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.

• Question 37:

  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.
  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.

  ---

  *(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

• Question 38:

  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.
  B. Migrate using Data Pump.
  D. Migrate using cross platform Transportable Database.

  ---

  B:Oracle Data Pump can be used to migrate an Oracle database to a new platform, and to move from an older release of the database to a newer release. Using Oracle Data Pump to move an E-Business Suite database is a well-documented and tested procedure, and can be used to migrate your database to the Oracle Exadata Database Machine and upgrade it to Oracle Database 11g release 2 (11.2) in the same exercise

  Reference:Migrating the Oracle E-Business Suite Database to Oracle Exadata Database Machine UsingTransportable Tablespaces

  Reference:Migrating Oracle E-Business Suite to Oracle Exadata Database Machine Using Oracle Data Pump

• Question 39:

  You are checking the status of the portson the one of the InfiniBand switches in yourDatabase Machine.

  You have run the getportstatusas shown:

  

  Youhave 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.
  B. Use the ibqueryerros.pl script logged into the InfiniBand switch as root.
  C. Use Database Control.

  ---

  B:ibqueryerrors.pl -rR -s

  LinkDowned,RcvSwRelayErrors,XmtDiscards,XmtWait

  ibqueryerrors.pl -s

  RcvSwRelayErrors,RcvRemotePhysErrors,XmtDiscards,XmtConstraintErrors,RcvConstrain tErrors, ExcBufOverrunErrors,VL15Dropped

  --- A single invocation of this command will report on all switch ports on all switches. Run this check from a database server or a switch.

  *Switch Port Configuration Monitor

  This metric is mainly used for monitoring the connectivity of ports and raising alerts when there is a disconnection.

• Question 40:

  You plan to monitor the status of the motherboard, memory, power, fans, and network cards on the database nodes in your Database machine using Enterprise Manager. Where must you set the thresholds for these hardware components and why to assure that sensor readings, faults any related alerts, are visible in Enterprise Manager?

  A. Set thresholds in ILOM and in Enterprise Manager because they are not preset anywhere and must be set in both places
  B. Set thresholds only in ILOM because they are not preset anywhere but need only be set in ILOM.
  C. No thresholds need be set because they are preset in the ILOM and in Enterprise Manager.
  D. No thresholds needho set because they are preset in the ILOM and these are sufficient for monitoring.
  D. No thresholds needho set because they are preset in the ILOM and these are sufficient for monitoring.

  ---

  Note:

  * The ILOM management interface is also integrated with Oracle Enterprise Manager Ops Center.

  *ILOM Features and Functionalityinclude:

  Remote hardware monitoringwhich include:

  Monitor customer-replaceable units (CRUs) and fieldreplaceable units (FRUs), including power supplies, fans, hostbus adapters (HBAs), disks, CPUs, memory, and motherboard *The ILOM-based service processor (SP) receives error

  telemetry about error events that occur within the major system components on the host (CPU, memory, and I/O hub) and the environmental subsystem within the chassis (such as fans, power supplies, and temperature). The components

  and conditions are then diagnosed as fault events and captured in the ILOM event log.