The ManyToManyRelationship makes it possible for you, the cube
designer, to add custom, many-to-many dimensions to an OLAP cube, for enabling
advanced analytic scenarios. Defining many-to-many relationships is beyond the
scope of this document. However, you can investigate this concept and its
benefits. For more information about the ManyToManyRelationship
During cube deployment, Service Manager automatically adds
many-to-many dimensions to the cube for all "one-hop" relationships,
without any interaction from you. However, Service Manager does not add
many-to-many dimensions for cascading (multi-hop) relationships because of the
exponential increase of possible relationships that could be added.
Adding all
these relationships can significantly degrade performance when the OLAP cube is
browsed. This is because the aggregations of many-to-many relationships are
generally not calculated during processing and because the joins will be
evaluated while the OLAP cube is browsed. If you want a specific, cascading,
many-to-many relationship, you can define the relationship using a management
pack element and it will be added to the OLAP cube.
Conversely, you can overwrite
an automatically generated, many-to-many relationship to use a different
intermediate measure group in instances in which multiple intermediate groups
exist. In this case, Service Manager automatically uses the first group that is
encountered. The following is an example of a many-to-many management pack
relationship element:
<ManyToManyRelationship
CubeDimension="ServiceDim"
TargetMeasureGroup="AlertAboutConfigItem"
IntermediateMeasureGroup="ServiceContainsConfigItem" />
The following table describes many to many relationship
attributes.
|
Attribute
|
Required
|
Values
|
Definition
|
|
CubeDimension
|
Yes
|
String
|
Name of the many-to-many cube
dimension
|
|
TargetMeasureGroup
|
Yes
|
String
|
The target measure group to create
the many-to-many relationship
|
|
IntermediateMeasureGroup
|
Yes
|
String
|
The intermediate measure group to
create the many-to-many relationship
|
No comments:
Post a Comment