Representation of metadata in a data warehouse

An active metadata catalogue is necessary in a data warehouse for users to find and analyse all the information within the warehouse. We outline an ontological analysis of the components of the data warehouse, along with the metadata required to describe these components. We propose the use of a description logic language to represent and reason with the knowledge in the ontology. Each component within the warehouse is specified as an item, and a meta-item reflects information about each item. As an example, we describe the metadata required for a dimension attribute in a fact table, within a sales schema for a data warehouse.