Clusters

A cluster is a schema object that contains data from one or more tables, which have one or more columns in common. Oracle Database stores together all the rows from all the tables that share the same cluster key.

PowerDesigner models clusters as extended objects with a stereotype of <<Cluster>>.

Note:

Clusters in Oracle v10gR2 and earlier are modeled as indexes with the Cluster check box selected. To upgrade such clusters to v11 or higher, you must generate a new PDM with the appropriate DBMS target from your original model. Simply changing the target DBMS will result in the loss of any existing clusters

Creating a Cluster

You can create a cluster in any of the following ways:

Select Model > Clusters to access the List of Clusters, and click the Add a Row tool
Right-click the model or package in the Browser, and select New > Cluster

Cluster Properties

You can modify an object's properties from its property sheet. To open a cluster property sheet, double-click its Browser in the Clusters folder.

The following extended attributes are available on the General tab:

Name	Description
Owner	Specifies the owner of the cluster

In addition, the following tabs are available:

Columns – lists the columns associated with the cluster
Indexes – lists the indexes defined for the cluster