Metadata is a slippery subject. It can mean many different things, and be in many different forms, but essentially it is information that describes:

• The physical constructs in the data warehouse (the tables and indexes etc),
• The processes that load the tables
• The usage, authorities, environment and events occurring the data warehouse

But why is it important? When you build a data warehouse, or data mart, you do so with the expectation that your users will access it. Power users will create their own reports and queries. These users need to know what it contains, what each table and column represent and possibly what transformations have been applied. To be successful, you need to supply this information – as metadata.

To be useful the metadata must be readily accessible, in a consistent format and user friendly. It also needs to be sustainable. Hard copy manuals will quickly get out of date. The metadata must be online and it must require a minimum of effort to ‘publish’ it to end users.

RODIN is a metadata driven tool. Developers create definitions in the metadata, from which RODIN builds objects and processes. Therefore complete and up to date metadata is always available. This can be made available to end users (in a browser) at the click of a button.