Dimensionality Modeling

• DM:for high-performance access

• DM:uses ER modeling with some important restrictions

• DM:star schema, star join Fig.33.2(32.1)

• fact table with a composite primary key
• a set of dimension tables with non-composite primary key(one of the components of the fact table's primary key)
• all natural keys replaced with surrogate key(based on simple integers)