Fact and Dimension Attributes (PDM)

Fact attributes are used by the fact for joins to dimensions or as the basis of calculated measures. Dimension attributes provide data points around which the data in a fact can be interrogated.

Creating an Attribute

Fact and dimension attributes are generally generated from operational database table columns. You can also manually create attributes as follows:
  • Open the Attributes tab in the property sheet of a fact or dimension, and click the Add a Row or Insert a Row tool. The Add Attributes tool allows you to reuse an attribute from another fact or dimension.

  • Right-click a fact or dimension in the Browser, and select New > Attribute.

Attribute Properties

To view or edit an attribute's properties, double-click its Browser or list entry. The property sheet tabs and fields listed here are those available by default, before any customization of the interface by you or an administrator.

The General tab contains the following properties:

Property

Description

Parent

Specifies the parent fact or dimension of the attribute.

Name/Code/Comment

Identify the object. The name should clearly convey the object's purpose to non-technical users, while the code, which is used for generating code or scripts, may be abbreviated, and should not normally include spaces. You can optionally add a comment to provide more detailed information about the object. By default the code is generated from the name by applying the naming conventions specified in the model options. To decouple name-code synchronization, click to release the = button to the right of the Code field.

Stereotype

Extends the semantics of the object. You can enter a stereotype directly in this field, or add stereotypes to the list by specifying them in an extension file.

Type Specifies how the value of the attribute is determined:
  • Standard - the attribute is mapped to the operational table column specified in the Mapped to field. To map a manually-created attribute to its source, open the Mapping Editor and drag and drop the column from the Source pane onto the attribute in the Target pane (see Operational to Warehouse Data Mappings).
  • Calculated - the attribute is calculated from an expression specified in the Formula expression field. Enter the expression directly or click the Edit with SQL Editor tool (see Writing SQL Code in the PowerDesigner SQL Editor).

Keywords

Provide a way of loosely grouping objects through tagging. To enter multiple keywords, separate them with commas.

Dimension attributes include the following tab:
  • Detail Attributes - Lists other dimension attributes that are use to further define the attribute. Click the Add Detail Attributes tool to select attributes defined on the current dimension to further define the attribute.

    In the following example, attributes Cust_Name and Cust_Address are used as detail attributes for Cust_ID: