This PPT explains SSIS Data flow task transformation that exists in SQL Server 2008 R2, it's the continuation of "http://www.slideshare.net/PramodSingla1/629-ssis-training2008r2-dataflowtransformations" PPT.
1. SCD Type 1
It is used when there is no need to store historical data in the dimension
table. This method overwrites the old data in the dimension table with the
new data. It is used to correct data errors in the dimension.
2. SCD Type 2
It stores the entire history the data in the dimension table. With type 2 we
can store unlimited history in the dimension table. In type 2, you can store
the data in three different ways. They are
• Effective Date
3. SCD Type 3
only the current status and previous status of the row is maintained in the
table. To track these changes two separate columns are created in the table.
Slowly Changing Dimensions (SCD) - Types
• It coordinates the updating and inserting of records in data warehouse
• only supports connections to SQL Server
• The Slowly Changing Dimension transformation supports four types of
– changing attribute (equivalent to a Type 1 change)
– historical attribute (equivalent to a Type 2 change)
– fixed attribute
– inferred member
• Type 3 changes not supported in SCD.
• The Slowly Changing Dimension transformation has one input and up to
– Fixed Attribute Output and Unchanged :No default data flow is created
SCD Tool in SQL Server
SCD Data Flow Diagram