What is Slowly changing dimension. And How many types of SCD's we have.

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Slowly changing dimension (SCD) is a concept in data warehousing that describes how dimensions change over time.

SCD Type 1: Overwrites old data with new data, losing historical information.
SCD Type 2: Keeps multiple versions of the same dimension, creating new records for each change.
SCD Type 3: Keeps both old and new values in the same record, with separate columns for each version.
SCD Type 4: Uses separate tables to store historical and current data.
SCD Type 6: Hybrid approach combining Type 1, Type 2, and Type 3 methods.
Example: In Type 2 SCD, if a customer changes their address, a new record is created with the updated address while keeping the old record for historical purposes.

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