Rules for Dimension Objects

When you create a dimension object using OWB, the dimension must conform to the following rules:

• A dimension must have a surrogate identifier and a business identifier.

• The surrogate identifier can consist of only one attribute. However, the business identifier can consist of more than one attribute.

• Every dimension level must have at least one attribute.

• A dimension attribute can be either a surrogate identifier, a business identifier, a parent identifier, or a regular attribute.

• A regular attribute can also play only one of the following roles at a time: effective date, expiration date, or triggering attribute.

• A dimension that uses a relational or ROLAP implementation must have at least one level.

• Any database table or view that implements a dimension that uses a relational or ROLAP implementation must have only one LONG, LONG RAW, or NCLOB column.

• For a dimension that uses a relational or ROLAP implementation, all level attributes must bind to database tables or views only.

• A dimension that uses a relational or ROLAP implementation must be associated with a sequence that is used to load the dimension key attribute.

• The dimension key attribute of a dimension that uses a relational or ROLAP implementation must bind to the primary key of a table.

• A Type 2 Slowing Changing Dimension (SCD) must have the effective date, expiration date, and at least one triggering attribute.

• A Type 3 Slowing Changing Dimension (SCD) must have the effective date and at least one triggering attribute.