Oracle 1Z0-515 Online Practice Questions and Exam Preparation

Oracle 1Z0-515 Online Questions & Answers

• Question 61:

  You can perform what-if analysis of potential changes with Oracle Warehouse Builder.

  A. TRUE
  B. FALSE
  A. TRUE

  ---

  The Metadata Dependency Manager (MDM) enables you to plan your project by previewing the impact of the changes or future changes for "what-if" analysis. When you plan to introduce changes to your source systems, you can gauge the impact of that change on your warehouse design. If changes have already been introduced, then you can plan the time required to update your ETL design and rebuild your data warehouse.

• Question 62:

  What would you use to evenly distribute data across the disk in your Oracle data warehouse?

  A. Range Partitioning
  B. Automatic Storage Management (ASM)
  C. List Partitioning
  D. RAC
  B. Automatic Storage Management (ASM)

  ---

  Automatic Storage Management (ASM) is a feature provided by Oracle Corporation within the Oracle Database from release Oracle 10g (revision 1) onwards. ASM aims to simplify the management of database files. To do so, it provides tools to manage file systems and volumes directly inside the database, allowing database administrators (DBAs) to control volumes and disks with familiar SQL statements in standard Oracle environments. Thus DBAs do not need extra skills in specific file systems or volume managers (which usually operate at the level of the operating system).

  With ASM:

  *

  IO channels can take advantage of data striping and software mirroring

  *

  DBAs can automate online redistribution of data, along with the addition and removal of disks/storage

  *

  the system maintains redundant copies and provides 3rd-party[citation needed] RAID functionality

  *

  Oracle supports third-party multipathing IO technologies (such as failover or load balancing to SAN access) the need for hot spares diminishes

• Question 63:

  You are looking to create a RAC cluster to deliver high performance for your client's data warehouse. Which statement is true about a configuration with a few large nodes versus a configuration with many smaller nodes?

  A. A few large nodes always perform better than many small nodes.
  B. A few large nodes always perform worse than many small nodes.
  C. It depends on the workload specifics and the effect of a node failure.
  D. Performance should be the same with either option.
  D. Performance should be the same with either option.

• Question 64:

  The Analytic Workspace Manager would be used to generate_______.

  A. Materialized views
  B. Oracle OLAP Option cubes
  C. Oracle Data Mining algorithms
  D. Oracle SQL Analytic functions
  B. Oracle OLAP Option cubes

  ---

  You can use Analytic Workspace Manager for creating measures, dimensions and cubes in the OLAP database if the database was installed with the OLAP option. Workspace Manager, a feature of Oracle Database, enables application developers and DBAs to manage current, proposed and historical versions of data in the same database.

  Note: Applications and DBA operations often work with more than one version of the data. Three common reasons to have multiple data versions are concurrency, auditing and scenario creation. Oracle Workspace Manager provides workspaces as a virtual environment to isolate a collection of changes to production data, keep a history of changes to data and create multiple data scenarios for "what if" analysis. It can save money, time and labor over traditional approaches.

• Question 65:

  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.
  B. Distribute workload to some of the nodes.

  ---

  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.

• Question 66:

  Identify the benefit of using bitmap join indexes. Select one.

  A. Faster query performance for all queries.
  B. Reduced space for indexes.
  C. Faster query performance for some queries.
  D. Lower memory usage.
  B. Reduced space for indexes.

  ---

  Oracle benchmarks claim that bitmap join indexes can run a query more than eight times faster than traditional indexing methods.

  However, this speed improvement is dependent upon many factors, and the bitmap join is not a panacea. Some restrictions on using the bitmap join index include:

  The indexed columns must be of low cardinality--usually with less than 300 distinct values. The query must not have any references in the WHERE clause to data columns that are not contained in the index. The overhead when updating

  bitmap join indexes is substantial. For practical use, bitmap join indexes are dropped and rebuilt each evening about the daily batch load jobs. This means that bitmap join indexes are useful only for Oracle data warehouses that remain read-

  only during the processing day.

• Question 67:

  You customer wants to segment their customers1 demographic data into those that use and do not use loyalty card. What would you recommend?

  A. Use Oracle OLAP Option.
  B. Use Oracle SQL Analytic Functions.
  C. Use classification algorithm in Oracle Data Mining.
  D. Use non-negative matrix factorization in Oracle Data Mining.
  C. Use classification algorithm in Oracle Data Mining.

  ---

  Classification is a data mining function that assigns items in a collection to target categories or classes. The goal of classification is to accurately predict the target class for each case in the data. For example, a classification model could be

  used to identify loan applicants as low, medium, or high credit risks. The simplest type of classification problem is binary classification. In binary classification, the target attribute has only two possible values: for example, high credit rating or

  low credit rating

  Note:

  Oracle Data Mining provides the following algorithms for classification:

  *

  Decision Tree

  Decision trees automatically generate rules, which are conditional statements that reveal the logic used to build the tree.

  *

  Naive Bayes

  Naive Bayes uses Bayes' Theorem, a formula that calculates a probability by counting the frequency of values and combinations of values in the historical data.

  *

  Generalized Linear Models (GLM)

  GLM is a popular statistical technique for linear modeling. Oracle Data Mining implements GLM for binary classification and for regression. GLM provides extensive coefficient statistics and model statistics, as well as row diagnostics. GLM

  also supports confidence bounds.

  *

  Support Vector Machine

  Support Vector Machine (SVM) is a powerful, state-of-the-art algorithm based on linear and nonlinear regression. Oracle Data Mining implements SVM for binary and multiclass classification.

• Question 68:

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

  ---

  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.

• Question 69:

  Your customer wants to implement an ILM strategy. The customer must have which option when deploying Oracle's ILM Assistant to implement this strategy?

  A. RAC
  B. Partitioning
  C. OLAP
  D. Oracle Clusterware
  B. Partitioning

  ---

  Information Lifecycle Management (ILM) is a set of policies and procedures for managing data during its lifetime.

  The ILM Assistant manages information by recommending the correct placement of data on logical storage tiers as specified by a lifecycle definition, where a lifecycle definition describes the stages and storage tiers that data resides on

  during its lifetime. Each stage specifies a retention period during which the data resides on a logical storage tier. A logical storage tier is a collection of Oracle tablespaces in which partitions may reside.

  Note: Information today comes in a wide variety of types, for example an E-mail message, a photograph, or an order in an Online Transaction Processing System. Therefore, once you know the type of data and how it will be used, you already

  have an understanding of what its evolution and final destiny is likely to be.

  One of the challenges facing each organization is to understand how its data evolves and grows, monitor how its usage changes over time, and decide how long it should survive, while adhering to all the rules and regulations that now apply

  to that data. Information Lifecycle Management (ILM) is designed to address these issues, with a combination of processes, policies, software, and hardware so that the appropriate technology can be used for each stage in the lifecycle of the

  data.

• Question 70:

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

  ---

  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.