Changing Dimensions

To add an Attribute

Click in the empty row at the end of the list.

• Attribute Name. Enter the attribute name. Spaces are replaced with _ when the dimension is saved. The Name must be unique within the dimension. Dimodelo Data Warehouse Studio will validate the name. If a name is specified that violates SQL Server naming restrictions, a red ! will be displayed on the row.
• Data Type. Select a data type from the dropdown list, or just type the data type. The data type will be validated to ensure it is a valid SQL Server data type when the data type field loses focus. If the data type is invalid, a dialog box will display, and the field cleared.
• Column Type. Choose the column type for the attribute. If the attribute is part of the Natural/Business key of the dimension, then select ‘Business Key’. The business key can be a composite key. That is, more than one attribute can have a type of Business Key. Normally the business key is what your ETL process will use to look up the dimension to identify if source rows already exist in the dimension. It is the primary key of the source table.
• SCD Type. SCD Type is an acronym for Slowly Changing Dimension Type. The list of types correspond to the SCD types set out by Ralph Kimball. When the Attribute type is ‘Attribute’ this field is enabled and is required. Select the appropriate SCD type for the attribute. The SCD type selected will affect how the DDL is generated for the attribute (using the supplied templates). Type 3 and 6 SCD Type attribute will have additional <attribute name>_Prev columns created for them. If you don’t understand SCD types then read our ‘Data Warehouse and Business Intelligence Concepts – Guide’.
• Description. Add a description of the attribute. Generally the description should make sense to an end user. Descriptions are used in the generated Data Dictionary.
• The parent indicator is used to indicate that the attribute is the natural key of the corresponding parent row in a parent-child hierarchy. That is, each row keeps its parent identifier in this attribute column. Parent identifiers can be composite keys, so more than 1 attribute can be marked as a Parent. The presence of a Parent indicator on any attribute will cause a Parent Surrogate Key to be generated in the DDL using the supplied DDL templates. Only a single Parent surrogate key is produced regardless of how many attributes are marked as Parent. Parent logic is added to the ETL Transformation if Parent is ticked.
• This is a free form text you can use to reference the attribute back to another design document, or perhaps a report the attribute appears on.

To Delete an Attribute

Select the attribute row and click the delete key, or click the Delete Attribute(s) button. You can select multiple rows.

To Change an Attribute

Simply find the attribute in the list, click in the field you want to change, and change as desired. Attribute name changes are generated in the DDL as non-destructive rename script. Changes are only made permanent after the document is saved.