Creating a Cube

1.   Once you have set up and selected the DSN, you will be returned to the Create Cube from Relational Source dialog box.

Note that the Data Source information (Driver and Name) is filled in per your selections in the previous dialog box.

2.   In the Cube/Name text box, name the Cube you want to build,
e.g., Order Information (as shown above).

Notes


Note the checkbox Support Incremental Updating. This option will be discussed on Building and Updating Cubes that Support Incremental Updating.

DATA SOURCE section Fields:

A brief description of each field under the Data Source section of the 'Create Cube From Relational Source' dialog box is provided below:

• Driver
  - This is a user specifies the ODBC driver for your database
  
• Data source name
  - This are displays the Data Source Name.
  
• User name / Password
  - This feature allows the creator of the Cube to specify a User name/Password when creating a Cube from the relational source, adding security and protection for the Cube, as well as convenience for the user. Now, by specifying a Username and Password to log onto the relational data source, this information will be kept with the Cube and used whenever a connection must be made to the source.

User Name and Password thus become the authentication required by the relational source in order for the user to login to the database.

Only the Administrator who creates the Cube needs the authentication information and he/she need not provide this information to the users, because they are no longer going to be prompted for it repeatedly.

CUBE section options:

In regard to the check boxes on the bottom left portion of the dialog box, provided below are brief description of these options.

• Cube Name
  - This is where a user specifies the name of the OLAP Exchange cube.
  
• Numeric Data Only
  - Check this box to ensure that the data contained in the measures table must contain numbers. (For this demonstration, enable this option)
  
• Multi-dimensional Editing Allowed
  - Check this box to be able to edit or make changes to the Fact Data of the detail elements of the multidimensional Cubes after the Cubes have been created. If the box is unchecked, Fact Data in the Cubes will be read only. (For this demonstration, do not enable this option)
  
• Allow View Tables
  - Check this box to allow access to views for creating Dimensions. If the option is checked, Incremental Updating will not be supported because Views are not supported by Triggers (see related topic, Preparing Relational Data for use with OLAP Exchange under Administrator Topics section). (For this demonstration, do not enable this option)
  
• Write Back to Relational Database
  - Check this box to allow write back of the Cube data into relational source tables.

This is an extremely advanced feature. When there is a change in a value in PowerOLAP database, PowerOLAP^® will use an ODBC call to write that value back to the transactional table. One requirement in order to write back to a relational database is that definition of a Cube must be one to one with the transactional structure. Situations where multiple transactional records make up one point in the PowerOLAP cube, write back cannot occur. It must be a relationship that every point in PowerOLAP^® has a corresponding point in the relational database.

Oftentimes, some type of transactional ID is used as one of the PowerOLAP dimensions.

Due to the complexity of the way it works, this is recommended for very advance users.

• Support Incremental Updating
  - This feature creates triggers in relational database to keep PowerOLAP^® updated. When enabled, this creates the necessary trigger based on the structure defined in OLAP Exchange^®. These triggers will populate auxiliary tables created by PowerOLAP^® whenever source data changes. In other words, Members and Fact Data will be created or modified within these additional relational structures. The triggers will then modify the information in those tables.

One advantage of Incremental Updating is that only changes that occur inside of the relational database are reflected in PowerOLAP^®. Incremental Updating is supported using various ODBC drivers, SQL Server, Oracle and DB2.

Once you have finished configuring your cube settings, proceed with the next step.

3.   After specifying Cube name and making appropriate selections in the dialog box, click OK.

The Dimensions dialog box appears (as shown in the following figure).

At this point, the cube is not yet created, you must first proceed with creating all the pertinent dimensions and finish synchronizing the data from the underlying relational database before the cube can be actually completed.