afzal

• May 22nd, 2006

 

A surrogate key is system genrated/artificial key /sequence number or A surrogate key is a substitution for the natural primary key.It is just a unique identifier or number for each row that can be used for the primary key to the table. The only requirement for a surrogate primary key is that it is unique for each row in the tableI it is useful because the natural primary key (i.e. Customer Number in Customer table) can change and this makes updates more difficult.but In my project, I felt that the primary reason for the surrogate keys was to record the changing context of the dimension attributes.(particulaly for scd )The reason for them being integer and integer joins are faster. Unlike other

shiva

• Aug 21st, 2006

 

Surrogate key is a Unique identifier for eatch row , it can be used as a primary key for DWH.The DWH does not depends on primary keys generated by OLTP systems for internally identifying the recods.When the new record is inserting into DWH primary keys are autimatically generated such type od keys are called SURROGATE KEY.Advantages1. Have a flexible mechanisam for handling S.C.D's2. we can save substantial storage space with integer valued surrogate keys.