An Essbase model is a logical model (star schema) that is created from tables and columns in a relational database. The Essbase model is used to generate the structure of an multidimensional database.
When you build a cube schema, you specify hierarchies, measures, and measure hierarchies to include in the cube. The Essbase model shows graphically the objects and joins that comprise a cube schema.
Essbase models are based on the concept that values in a source database can be categorized as either facts or dimensions of facts. Facts are the numeric, variable values in the database, such as sales figures and the number of units sold.
Dimensions are data categories used to organize data for retrieval and preservation of values. Dimensions usually contain hierarchies of related members grouped within them. For example, a Year dimension often includes members for each time period, such as quarters and months. Dimensions are often related to business functions. Product, Region, and Year are typical dimensions. For more information on dimensions, see Dimensions Overview.
Associated with facts are related data values that provide additional information, such as store locations and product IDs of units sold. An Essbase model contains a fact table, dimension tables, dimension branches, and optional time and accounts dimensions. You can also tag columns in a hierarchy to be attribute-enabled. These columns become attributes such as color or size, in the outline and provide an additional layer of reporting in Essbase.
An Essbase model that you create with Essbase Studio is a logical model, not a physical star schema. The model is a logical representation of the data values that you select from the source database tables and that you want to report in Essbase. You use a model to create outlines which contain the basic structure required to load data into Essbase.
You can create multiple models from the same schema, edit the properties of each model, and then deploy each model to one or more Essbase outlines.
Essbase models have the following features:
They are reusable. You can use the same model as the basis for more than one outline.
They provide a layer of abstraction that insulates the database outline from changes in the source database.
They enable you to create hierarchies to structure and summarize the data from the source database. You can use these hierarchies in multiple outlines.
They support OLAP and XOLAP environments.
See OLAP Overview and XOLAP Overview.
You specify building an Essbase model either during the cube schema creation process or, later, from an existing cube schema. One cube schema can have multiple Essbase models associated with it.
Use the Essbase Model Properties dialog box to modify properties of an Essbase model before you deploy it. You can also view and edit properties at other levels. See Dimensions Overview and Member Properties.
The Essbase Model Properties dialog box has three tabs for editing model properties:
General tab—Setting General Model Properties
Alias tab—Selecting Tables as Alias Sets
Attributes tab—Defining Attributes in Models