Composers

A composer in DWD combines data from different data sources into one new component that can be reused in many dimension or fact tables. In a composer, you combine data from different tables. A composer is a collection of columns from one or many source objects, Splitters, and Decoders.

Composers are the foundation in information models and BMMs. A composer is built and stored in the DWD catalog on the data warehouse server.

The important points to remember when creating or editing composers are:

• Keys: all source object keys should be included in the composer so that the data mart retains the ability to provide drill down in a dimension.

• Relations: each dimension has a hierarchy that you set up in DWD Designer tables or fact tables. Use the Relation Manager to set relations within and between design that includes one or more data marts. Managing Relations

If you use the pre-designed information models, you do not need to design composers.