Join index; Join indices; Star index
A star index is a collection of join indices, one for every foreign key join in a star or snowflake schema.
A common structure for a data warehouse is a fact table consisting of several dimension fields and several measure fields. To reduce storage costs, the fact table is often normalized into a star or a snowflake schema. Since most queries reference both the (normalized) fact tables and the dimension tables, creating a star index can be an effective way to accelerate data warehouse queries. The Red Brick data warehouse system has implemented star indices.