1Z0-515 Online Practice Questions and Answers

Correct Answer: B

Explanation:

Reference partitioning is a partitioning method introduced in Oracle 11g. Using reference partitioning, a

child table can inherit the partitioning characteristics from a parent table.

Correct Answer: B

Explanation:

Substring functions are not analytic.

Correct Answer: B

Explanation:

With Oracle RAC the workload can be distributed access all cluster nodes, parallel query servers can be provided through the Parallel Query tool, and high availability can be obtained through, for example, Oracle Clusterware.

Note: Oracle RAC (Real Application Clusters) is a cluster database with a shared cache architecture that overcomes the limitations of traditional shared-nothing and shared-disk approaches to provide highly scalable and available database solutions for all your business applications. Oracle RAC is a key component of Oracle's private cloud architecture. Oracle RAC support is included in the Oracle Database Standard Edition for higher levels of system uptime. References:

Correct Answer: A

Explanation:

Table storage requirements would increase, but the benefits are huge.

Oracle partitioning is a divide-and-conquer approach to improving Oracle maintenance and SQL performance. Anyone with un-partitioned databases over 500 gigabytes is courting disaster. Databases become unmanageable, and serious problems occur:

*

SQL may perform poorly - Without Oracle partitioning, SQL queries with full-table scans take hours to complete. In a full scan, the smaller the Oracle partition, the faster the performance. Also, index range scans become inefficient.

*

Recovery - Files recovery takes days, not minutes

*

Maintenance - Rebuilding indexes (important to re-claim space and improve performance)

Oracle partitioning has many benefits to improve performance and manageability:

*

Stable

*

Robust

*

Faster backups

*

Less overhead

*

Easier management Maintenance of Oracle partitioned tables is improved because maintenance can be focused on particular portions of tables. For maintenance operations across an entire database object, it is possible to perform these operations on a per-partition basis, thus dividing the maintenance process into more manageable chunks. (not D)

*

Faster SQL Oracle is partition-aware, and some SQL may improve is speed by several orders of magnitude (over 100x faster).

-Index range scans Oracle partitioning physically sequences rows in index-order causing a dramatic improvement (over 10x faster) in the speed of partition-key scans.

-Full-table scans Oracle partition pruning only accesses those data blocks required by the query.

-Table joins Oracle partition-wise joins take the specific sub-set of the query partitions, causing huge speed improvements on nested loop and hash joins. (not C)

-You can also improve the performance of massive join operations when large amounts of data (for example, several million rows) are joined together by using partition-wise joins. (not B)

-Updates Oracle parallel query for partitions improves batch load speed.

References:

Correct Answer: ACD

Explanation:

There are three major advantages of partitioning.

*

Partition Pruning - Oracle only accesses a limited set of table partitions if the FROM and WHERE clause

permit it to.

*

Partition-wise Joins - Where two tables that have compatible partitioning schemes are joined , Oracle

improves the efficiency of parallel operations by performing the join between individual partitions of the

tables.

*

Manageability - Partitioning allows DDL operations on a large subset of table rows with some element of

commonality defined through the partitioning type.

References:

Correct Answer: A

Explanation: Partitioning enhances the performance, manageability, and availability of a wide variety of applications and helps reduce the total cost of ownership for storing large amounts of data. Partitioning allows tables, indexes, and index-organized tables to be subdivided into smaller pieces, enabling these database objects to be managed and accessed at a finer level of granularity. Oracle provides a rich variety of partitioning strategies and extensions to address every business requirement. Moreover, since it is entirely transparent, partitioning can be applied to almost any application without the need for potentially expensive and time consuming application changes.

References:

Correct Answer: C

Explanation: Oracle Advanced Security is an option to the Oracle Database 11g Enterprise Edition that helps address privacy and regulatory requirements including the Payment Card Industry Data Security Standard (PCIDSS), Health Insurance Portability and Accountability Act (HIPAA), and numerous breach notification laws. Oracle Advanced Security provides data encryption and strong authentication services to the Oracle database, safeguarding sensitive data against unauthorized access from the network and the operating system. It also protects against theft, loss, and improper decommissioning of storage media and database backups.

References:

Correct Answer: A

Explanation: Data Mining and Data Warehousing Data can be mined whether it is stored in flat files, spreadsheets, database tables, or some other storage format. The important criteria for the data is not the storage format, but its applicability to the problem to be solved. Proper data cleansing and preparation are very important for data mining, and a data warehouse can facilitate these activities. However, a data warehouse will be of no use if it does not contain the data you need to solve your problem. Oracle Data Mining requires that the data be presented as a case table in single-record case format. All the data for each record (case) must be contained within a row. Most typically, the case table is a view that presents the data in the required format for mining Note: Oracle Warehouse Builder (OWB) enables the design and deployment of enterprise data warehouses, data marts, and e-business intelligence applications.

References:

Correct Answer: B

Explanation:

ASM is a management tool, not a RAW performance tool.

Note:

Automatic Storage Management (ASM) is a new feature that has be introduced in Oracle 10g to simplify

the storage of Oracle datafiles, controlfiles and logfiles.

Automatic Storage Management (ASM) simplifies administration of Oracle related files by allowing the

administrator to reference disk groups rather than individual disks and files, which are managed by ASM.

The ASM functionality is an extention of the Oracle Managed Files (OMF) functionality that also includes

striping and mirroring to provide balanced and secure storage. The new ASM functionality can be used in

combination with existing raw and cooked file systems, along with OMF and manually managed files.

The ASM functionality is controlled by an ASM instance. This is not a full database instance, just the

memory structures and as such is very small and lightweight.

The main components of ASM are disk groups, each of which comprise of several physical disks that are

controlled as a single unit. The physical disks are known as ASM disks, while the files that reside on the

disks are known as ASM files. The locations and names for the files are controlled by ASM, but user-

friendly aliases and directory structures can be defined for ease of reference. The level of redundancy and

the granularity of the striping can be controlled using templates. Default templates are provided for each

file type stored by ASM, but additional templates can be defined as needed.

Failure groups are defined within a disk group to support the required level of redundancy. For two- way

mirroring you would expect a disk group to contain two failure groups so individual files are written to two

locations.

In summary ASM provides the following functionality:

*Manages groups of disks, called disk groups.

*Manages disk redundancy within a disk group.

*Provides near-optimal I/O balancing without any manual tuning. *Enables management of database

objects without specifying mount points and filenames.

*Supports large files.

References:

Correct Answer: A

Explanation:

Without any redundancy (high performance is the only goal) you can use 100% of the disk space to data.

With disk mirroring (with lower performance) you can use 50% of the disk space to data.