Written by DBADMIN
Wednesday, 19 May 2010 03:21
SCD is abbreviation of Slowly changing dimensions. SCD applies to cases where the attribute for a record varies over time.
There are three different types of SCD.
1) SCD1 : The new record replaces the original record. Only one record exist in database - current data.
2) SCD2 : A new record is added into the customer dimension table. Two records exist in database - current data and previous history data.
3) SCD3 : The original data is modified to include new data. One record exist in database - new information are attached with old information in same row.