What is a surrogate key and why use them?

Question

A surrogate key is a unique key for an entity in the client's business or for an object in the database. Sometimes natural keys cannot be used to create a unique primary key of the table. This is when the data modeler or architect decides to use surrogate or helping keys for a table in the LDM.

What is a surrogate key what are its advantages?

A surrogate key (or synthetic key, pseudokey, entity identifier, factless key, or technical key) in a database is a unique identifier for either an entity in the modeled world or an object in the database. The surrogate key is not derived from application data, unlike a natural (or business) key.

What is the purpose of surrogate key in data warehouse?

Surrogate keys essentially buffer the data warehouse from the operational environment by making it immune to any operational changes.

Are surrogate keys necessary?

In a data warehouse, a surrogate key is a necessary generalization of the natural production key and is one of the basic elements of data warehouse design. Let's be very clear: Every join between dimension tables and fact tables in a data warehouse environment should be based on surrogate keys, not natural keys.

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