Databases Reference
In-Depth Information
Customer
Promotion
Store
Product
Time
Warehouse
Units Sold
Units Sold
Sales
Warehouse
FIGURE 7.3
Cube with two measure groups
In DDL, a measure group (fact) is a major object and, therefore, is defined and edited inde-
pendently of the other objects in the system. As any other major object, a measure group
has
ID
,
Name
,
Description
,
Annotations
, and
Translations
properties. A measure group
doesn't have its own language; it takes on the language property of the cube to which it
belongs. In addition, a measure group contains time and date stamps that indicate when it
was created and loaded with data.
Of the many properties of a measure group, some belong to the physical model: those that
define what data is loaded into the cube and how it is stored there. We discuss those prop-
erties in Chapter 20, “Physical Data Model.” Here, we go into detail about the properties
that define the conceptual data model. Table 7.2 describes those properties.
TABLE 7.2
Measure Group Properties
Property
Description
The type of measure group, such as
Exchange Rate
or
Inventory
. Analysis Services doesn't use the
Type
prop-
erty internally, but the property can be passed to the client
application for better visualization of the model.
Type
A list of the measures that make up the fact. The fact
must contain at least one measure.
Measures
The collection of dimensions that define the granularity
and the binding of the fact to the multidimensional space
of the cube. Each dimension can have a different relation-
ship to the fact. We cover those relationships in more
detail in Chapter 8.
Dimensions
Defines the behavior of the model when data is retrieved
from the measure group by dimensions that are not used
in the fact. In this case, there are two possible behaviors:
Such dimensions are ignored and data is retrieved using
other dimensions; or such dimensions are used, and the
data is considered missing for such request.
IgnoreUnrelatedDimensions
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