Measures (PDM)

Measures are mapped to numerical columns in fact tables and aggregate the values in the columns along the selected dimensions. For example, when a user chooses to view the sales in Texas in 2012 Q1, the calculation is performed via the Sales measure using a Sum aggregation. Measures can also be based on operations or calculations or derived from other measures.

Creating a Measure

Measures are generally generated from numerical columns in operational database tables. You can also manually create measures from the property sheet of, or in the Browser under, a fact.

Open the Measures tab in the property sheet of a fact, and click the Add a Row tool.
Right-click a fact in the Browser, and select New > Measure.

Measure Properties

To view or edit a measure'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 of the measure. Click the Properties tool to open the fact property sheet.
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 measure is determined. In each case, specify the aggregation function to be applied to values and then choose from: `Standard` - the measure is mapped to the operational table column specified in the Mapped to field. To map a manually-created measure to its source, open the Mapping Editor and drag and drop the column from the Source pane onto the measure in the Target pane (see Operational to Warehouse Data Mappings). `Calculated` - the measure 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). `Restricted` - the measure is derived from the measure specified in the Base measure field, and constrained by the values specified for each of the fact or dimension attributes added to the list.
Hidden	Specifies that the measure will not be visible to business users consulting the cube.
Keywords	Provide a way of loosely grouping objects through tagging. To enter multiple keywords, separate them with commas.