1z0-591 Exam Dumps - Oracle Certification Questions and Answers

Initialization blocks are used to initialize dynamic repository variables, system session variables, and nonsystem session variables.

Ragged Hierarchies are hierarchies where some routes down the hierarchy are longer than others; for example, you may have an organizational hierarchy for salespeople where the overall boss has two assistant managers, one of them works on their own and another has three sales managers under them; some of those sales manager may have sales staff under them, and some sales staff may have trainees under them.

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

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.

Web Catalog does contain object permissions: folder, reports, etc. The repository has objects permissions to Subject Areas, etc.

Note: A level-based measure is a column whose values are always calculated to a specific level of aggregation.

The calculation of this measure is independent of the query grain and used always the aggregation grain of the logical column.

Level-based measures allow :

* to return data at multiple levels of aggregation (the query grain and the level-based column grain) with one single query

* to create share measures (percentage), that are calculated by taking some measure and dividing it by a level-based measure. For example, you can divide salesperson revenue by regional revenue to calculate the share of the regional revenue each salesperson generates.

Modeling Time Series Function in OBIEE

Modeling Time Series Data

Time series functions provide the ability to compare business performance with previous time periods, allowing you to analyze data that spans multiple time periods. For example, time series functions enable comparisons between current sales and sales a year ago, a month ago, and so on.

Because SQL does not provide a direct way to make time comparisons, you must model time series data in the Oracle BI repository. First, set up time dimensions based on the period table in your data warehouse. Then, you can define measures that take advantage of this time dimension to use the AGO, TODATE, and PERIODROLLING functions.

Oracle Essbase developers creating planning and budgeting applications have been keenly aware of the advantages and disadvantages of the two different storage types available to them:

* Block storage option (BSO) databases support a wide range of calculations, including forecasts, allocations, and aggregations through procedural calculation scripts. The results of these calculations can be written back to the database, but applications that use BSO storage are limited to about 10 dimensions and member counts in the low hundreds of thousands.

* Aggregate storage option (ASO) databases can support about 20 dimensions and member counts in the millions. ASO databases use multidimensional functions rather than procedural scripts to perform calculations, but the results of queries cannot be stored back in the database, making ASO unsuitable for most financial management applications.

With the advent of 11G, MapViewer is installed as part of Oracle BI Enterprise Edition and deployed in the same domain as Oracle BI EE on the Web application server.

Before content designers can create map views, in the Manage map Data Administration page, the metadata must be configured:

* layers (theme) and map (zoom level)

* the mapping between Oracle BI EE data and spatial data

You have three sort of fragmentation:

Fact-based / Dimension-based fragmentation

Content-based / Value-based fragmentation

Level-based fragmentation / aggregate navigation

You can combine the techniques above to construct powerful design that are known as Complex partitioning / fragmentation. When you fragment a dimension, you are automatically in a complex fragmentation.