Extended Star Schema
· In Star Schema Fact tables are connected to Dimension tables only. But Extended Star Schema Fact table is connected to Dimension table and the Dimension table is connected to SID (Surrogate ID) table and SID table is connected to the master data tables.
· One Fact table connected to 16 Dimension tables, one Dimension table can be assigned with maximum of 248 SID Tables in Extended Star schema.
· Main Advantage of Extended Star schema is keeping the master data outside of dimension tables , we are able to share the master data across the system there by reducing the need of redundancy of master table.
· It is mainly used in SAP BW projects for fast loading of data and fast access to reports.