Defining Dimensions

Dimensions, hierarchies, and attributes

Before you can define any other objects, you must define the dimensions of your data. You can use the Dimension Creation Wizard or supply information directly in the Create Dimension dialog box.

To define a dimension, you provide all the information that will be needed to label and aggregate the measures dimensioned by it, including:

• The name of the dimension

• The tables that contain the data for the dimension

• The name of each level, and the columns that contain the data for each level

• The number and order of levels in each hierarchy

• Join keys for levels that are stored in separate tables

• The columns that contain attributes for the levels

• A display name and description for the dimension and each of its hierarchies, levels, and attributes

Time dimensions

Business analysis is performed on historical data, so fully defined time periods are vital. Special support for time dimensions is built into the metadata to allow for time-dependent analyses, such as comparisons with earlier time periods.

Your time dimension table must have columns for end-date and time-span, as described in "Time dimensions". Typical levels and hierarchies for time dimensions are suggested by the Dimension Wizard, but you do not have to use them.

Procedure: Defining dimensions

Follow these steps to create a dimension and its associated levels, hierarchies, and attributes:

1. Start Oracle Enterprise Manager and access OLAP management, as described in "Procedure: Accessing OLAP management".

2. To create a new dimension, right click on Dimensions, then choose one of the following:
   • Create Using Wizard to run the Dimension Wizard

     or

   • Create to edit a new dimension property sheet

3. Choose Help if you need additional information.

Figure: Dimension property sheet

The following figure shows the General page of the dimension property sheet for a Time dimension.

Related information

Search for the following topics in Oracle Enterprise Manager Help for information about creating dimensions:

"Creating Dimensions"

"Dimension Property Sheet"

"OLAP Dimension Management"

"What Is a Dimension?"