Oracle Oracle Certifications 1Z0-591 Questions & Answers

• Question 71:

  When creating a query. Subject areas can be combined via point and click as long as____.

  A. the subject areas share objects of the same name

  B. the subject areas both share the same model in the business model and mapping layer

  C. the subject areas are both from the same physical source, though they may be in separate business layers

  D. two or more subject areas cannot be joined together without manually mapping the contents

  Correct Answer: B

  Explanation: Users in Oracle BI Answers can create queries that span multiple subject areas, as long as the subject areas correspond to the same business model.

• Question 72:

  Pre Deployment sign-off is a milestone for a OBIEE implementation and is based on successful completion of certain tasks. Which option is not one of them?

  A. Test Environment

  B. System Testing

  C. Performance Tuning

  D. Project initiation and resourcing

  E. Data Validation / Verification

  Correct Answer: D

• Question 73:

  How will you model a Type II Slowly-Changing Dimension?

  A. Add an additional column to the dimension table to capture a version of change

  B. Overwrite an existing dimension table record with the changed record

  C. Add a new row to the dimension table with a new key for the changed record

  D. Do Nothing

  Correct Answer: C

  Explanation: Dimensional Modeling - Slowly Changing Dimensions

  *

  Type 1 - Overwrite Original Value

  A change does not require tracking

  *

  Type 2 - Add a new record

  With Type II SCD, a new version of the dimension record (row) is created, and the existing version is marked as history.

  Each row does not correspond to a different instance of an entity but a different "state", a "snapshot" of the instance at a point in time.

  Note: Tracking changes in dimension is referred in datawarehousing as slowly changing dimensions.

  In the source system a lot of changes are daily made :

  new customers are added,

  addresses are modified,

  new regional hierarchies are implemented,

  or simply the product descriptions and packaging change.

  These sorts of changes need to be reflected in the dimension tables and in several cases, the history of the changes also needs to be tracked.

  By remembering history, we are then able to look at historical data and compare it to their current situation.

• Question 74:

  Cache in OBIEE is used to_____. Select the two correct answers.

  A. improve performance of Dashboards and Analysis

  B. decrease query response time

  C. improve Analysis data quality

  D. eliminate Write Back Capabilities

  E. create Aggregate tables

  Correct Answer: AB

  Explanation: Decrease query response time which will improve performance for Dashboards and Analysis.

• Question 75:

  A customer frequently queries multiple dimension tables without a measure. What needs to be defined in the presentation layer?

  A. Logical Key

  B. Implicit Fact Column

  C. Alias

  D. Logical Column Name

  E. Custom Display Name

  Correct Answer: D

  Explanation: You can define calculations in either of the following ways:?Before the aggregation, in the logical table source. For example:sum(col_A *( col_B))?After the aggregation, in a logical column derived from two other logicalcolumns. For example:sum(col A) * sum(col B)

• Question 76:

  A customer needs to do a cross database join between two tables where, one of the tables has a small number of values and the other has a large number of values. How can you optimize the way the BI Server processes the query?

  A. By specifying a one-to-many join between the tables with the small and large numbers of values

  B. By specifying a driving table

  C. By specifying a many to one join between the tables with the small and large numbers of values

  D. By creating your logical join by using the Joins Manager

  E. By creating your joins by using the Business Model Diagram

  Correct Answer: B

  Explanation: You can specify a Driving table parameter in a complex join.

  Driving tables are for use in optimizing the manner in which the Oracle BI Server processes cross-database joins when one table is very small and the other table is very large.

  The BI Server will query the driving table (the small one) and will get a list of values. The BI Server will then generate a second SQL using a parameterized IN list with the values from the first query.

  Specifying driving tables leads to query optimization only when the number of rows being selected from the driving table is much smaller than the number of rows in the table to which it is being joined.

• Question 77:

  Why is it necessary to join multiple source tables to a single dimension?

  A. Because transactional source systems are often denormalized

  B. Because transactional source systems are often normalized

  C. Because a single source table often contains all the dimensions needed

  D. Because the dimensions tables are built in the transactional systems

  Correct Answer: B

  Explanation: Denormalized data in the transactional system could be divided into different tables to increase performance.

• Question 78:

  Query Limits are used to manage Query environment in the repository for users and roles and can_________.

  A. Control runaway queries

  B. Limit Queries by maximum run time

  C. Control aggregation

  D. Control User Authentication

  E. Control Write Back Capabilities

  Correct Answer: B

  Explanation: Query Limits. You can limit queries by the number of rows received, by maximum run time, and by restricting to particular time periods. You can also allow or disallow direct database requests or the Populate privilege. See figure below.

  

• Question 79:

  A derived measure is never used to_________.

  A. Calculate share measures

  B. Add two logical columns together

  C. Calculate a variance between two measures

  D. Calculate the rank dimension values

  E. Input data

  Correct Answer: E

• Question 80:

  What are the two types of Session Variables?

  A. System

  B. Non System

  C. Static

  D. Dynamic

  Correct Answer: AB

  Explanation: There are two types of session variables:

  System -- A session variable that the Oracle BI Server and Oracle BI Presentation Services use for specific purposes.

  System session variables have reserved names that cannot be used for other kinds of variables (such as static or dynamic repository variables and non-system session variables).

  Non-system -- A system variable that the administrator creates and names. For example, the administrator might create a SalesRegion non-system variable that initializes the name of a user's sales region.

  The administrator creates non-system session variables using the Oracle BI Administration Tool.

  Note: Session Variables

  A session variable is a variable that is initialized at login time for each user. When a user begins a session, the Oracle BI Server creates a new instance of a session variable and initializes it. There are as many instances of a session variable as there are active sessions on the Oracle BI Server. Each instance of a session variable could be initialized to a different value.