in star schema master data tables are inside the cube.

demerit of star schema
limited analysis is possible since only 16 master data 
table can be accommodated in a cube.  

alpha nummerical values are getting posted in fact table 
that may degrade the perfomence.

master data table cant reuse for any other cubes. 

in ext. star schema

Surrogat id tables are genearated with the activation of  
master data table. based on sids dimention id will genarate 
and the dimention id will get posted in fact table.

so charactorstic value will not be there fact table insted 
did's and kf will be there.

master data table can be re used since its out side of the 
cube. 

3224 master data table can be used in fact table through 
dimention table.