Is MySQL ENUM Really Efficient for Storing Small Data Sets?

Performance Implications of Using MySQL Enum for Small Value Sets

Despite the seemingly reduced space requirement for storing 5-10 different possible values, using the ENUM type in MySQL can actually incur performance penalties.

Reasons for Performance Penalty:

• Querying Permitted Values: Fetching the list of permitted values for an ENUM requires querying the information schema and parsing a BLOB field.
• Altering Permitted Values: Modifying the set of permitted values necessitates an ALTER TABLE statement, leading to table locking and potential restructuring.

Advantages of Lookup Tables Over ENUM:

Given the performance disadvantages, it's recommended to consider using lookup tables instead of ENUM. Here's the rationale:

• Faster queries to retrieve permitted values.
• Easier and faster updates to the set of permitted values.
• Avoids the data integrity issues that can arise with ENUM values being stored as numeric codes.

Conclusion:

While ENUM may appear to be efficient for storing a small number of distinct values, it can incur significant performance penalties for certain operations. For improved performance and flexibility, it's advisable to use lookup tables as an alternative to ENUM in such scenarios.

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