Disadvantages of the Surrogate Key

Surrogate Key

A surrogate key also called a synthetic primary key, is generated when a new record is inserted into a table automatically by a database that can be declared as the primary key of that table. It is the sequential number outside of the database that is made available to the user and the application or it acts as an object that is present in the database but is not visible to the user or application....

Features of the Surrogate Key

It is automatically generated by the system. It holds an anonymous integer. It contains a unique value for all records of the table. The value can never be modified by the user or application. The surrogate key is called the factless key as it is added just for our ease of identification of unique values and contains no relevant fact(or information) that is useful for the table....

Why use Surrogate Key in DBMS?

There are several reasons to use surrogate keys in database tables:...

Advantages of the Surrogate Key

As there is no direct information related with the table, so the changes are only based on the requirements of the application. Performance is enhanced as the value of the key is relatively smaller. The key value is guaranteed to contain unique information . As it holds smaller constant values , this makes integration of the table easy . Enables us to run fast queries (as compared to the natural primary key)...

Disadvantages of the Surrogate Key

The surrogate key value can never be used as a search key. As the key value has no relation to the data of the table, so third normal form is violated. The extra column for surrogate key will require extra disk space. We will need extra IO when we have to insert or update data of the table....

Conclusion

Surrogate keys are an important tool for designing and implementing databases. They can be applied to enhance database systems’ flexibility, stability, and performance....