Oracle Others Oracle Certifications 1Z0-515 Questions & Answers

• Question 61:

  You want partitions to be automatically created when data that does not fit into current date range loaded. Which type of partitioning would you implement?

  A. Hash

  B. List

  C. Invisible

  D. Interval

  Correct Answer: D

  Explanation: Interval Partitioning was introduced in 11g, interval partitions are extensions to range partitioning. These provide automation for equi-sized range partitions. Partitions are created as metadata and only the start partition is made persistent. The additional segments are allocated as the data arrives. The additional partitions and local indexes are automatically created.

  Note: Partitioning is one of the most sought after options for data warehousing. Almost all Oracle data warehouses use partitioning to improve the performance of queries and also to ease the day-to-day maintenance complexities. Starting with 11G, more partitioning options have been provided and these should reduce the burden of the DBA to a great extent.

  References:

• Question 62:

  For data warehousing, identify the benefits that would NOT be provided by the use of RAC.

  A. Distribute workload across all the nodes.

  B. Distribute workload to some of the nodes.

  C. Provide parallel query servers.

  D. Provide high availability for all the operations.

  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:

• Question 63:

  You think that result set caching might provide some benefits for your current data warehouse scenario. You perform some analysis on the composition of the queries used in the scenario. Identify the result of the analysis that would indicate the most potential for improvement with result set caching.

  A. The scenario consists mainly of queries that are used infrequently.

  B. The scenario consists mainly of queries that work on data which changes frequently.

  C. The scenario consists mainly of queries with long run times and small result sets.

  D. All data warehouse scenarios will benefit from result set caching.

  Correct Answer: C

  Explanation: As its name suggests, the query result cache is used to store the results of SQL queries for re-use in subsequent executions. By caching the results of queries, Oracle can avoid having to repeat the potentially time-consuming and intensive operations that generated the resultset in the first place (for example, sorting/aggregation, physical I/O, joins etc). The cache results themselves are available across the instance (i.e. for use by sessions other than the one that first executed the query) and are maintained by Oracle in a dedicated area of memory. Unlike our homegrown solutions using associative arrays or global temporary tables, the query result cache is completely transparent to our applications. It is also maintained for consistency automatically, unlike our own caching programs. References:

• Question 64:

  You will be implementing a data warehouse for one of your customers. In your design process, which index type is most likely to be used to improve the performance of some queries where the data is of low cardinality?

  A. Bitmap indexes

  B. B*-tree indexes

  C. Reverse indexes D. Invisible indexes

  Correct Answer: A

  Explanation:

  Bitmap indexes are a highly compressed index type that tends to be used primarily for data warehouses.

  Characteristic of Bitmap Indexes

  *

  For columns with very few unique values (low cardinality)

  *

  Columns that have low cardinality are good candidates (if the cardinality of a column is <= 0.1 % that the column is ideal candidate, consider also 0.2% 1%)

  *

  Tables that have no or little insert/update are good candidates (static data in warehouse)

  *

  Stream of bits: each bit relates to a column value in a single row of table

  References:

• Question 65:

  How many Exadata Storage Server cells can be used in a grid?

  A. 7

  B. 14

  C. 128

  D. No practical limit

  Correct Answer: D

  Explanation:

  There is no practical limit to number of cells that can be in the grid.

  References:

• Question 66:

  Identify the action that you CANNOT perform using Database Resource Manager.

  A. Define Consumer Groups.

  B. Create rules to map sessions to Consumer Groups.

  C. Define a Resource Plan.

  D. Allocate individual CPUs to Consumer Groups.

  Correct Answer: D

  Explanation:

  Oracle Database Resource Management (DRM) provides tools that allow any Oracle DBA to manage a

  database server's CPU resources effectively for application user groups and during different resource

  demand periods.

  DRM consists of four basic components:

  *Resource Consumer Groups (not A). A resource consumer group is a collection of users with similar

  requirements for resource consumption. Users can be assigned to more than one resource consumer

  group, but each user's active session can only be assigned to one resource consumer group at a time.

  *Resource Plans (not C). In its simplest form, a resource plan describes the resources allocated to one or

  more resource consumer group(s).

  *Resource Plan Directives (not B). Resource plan directives allocate resources among the resource

  consumer groups in the resource plan. Essentially, directives connect resource consumer groups or

  subplans to their resource plans.

  * SYSTEM_PLAN. Oracle supplies an initial, default resource plan named SYSTEM_PLAN. This plan implements a CPU utilization resource allocation method to divide and prioritize CPU resources to three resource consumer groups

• Question 67:

  Which is NOT among Oracle SQL Analytic functions included in Oracle Database 11g?

  A. Ranking functions

  B. Substring functions

  C. Window aggregate functions

  D. LAG/LEAD functions

  Correct Answer: B

  Explanation:

  Substring functions are not analytic.

• Question 68:

  Identify the control structure that would NOT be defined as part of a data flow with Oracle Data Integrator.

  A. Loops

  B. Conditions

  C. Error handling

  D. GOTOs

  Correct Answer: D

  Explanation:

  GOTOs cannot be used within the Oracle Data Integrator.

  References:

• Question 69:

  For which type of query is the SQL result cache automatically disabled?

  A. Queries that access data which changes frequently

  B. Queries that return large amounts of data

  C. Queries that use SQL functions such as SYSDATE

  D. Queries that are used infrequently

  Correct Answer: C

  Explanation:

  SYSDATE produces a new value every time it is used. Caching such a value would make no sense.

• Question 70:

  Indentify the true statement about REF partitions.

  A. REF partitions have no impact on partition-wise joins.

  B. Changes to partitioning in the parent table are automatically reflected in the child table.

  C. Changes in the data in a parent table are reflected in a child table.

  D. REF partitions can save storage space in the parent table.

  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.