Is Using MySQL ENUM Really Faster Than Lookup Tables?

Is There a Performance Advantage to Using MySQL ENUM?

Using ENUM when a field has only a limited range of possible values (5-10) is a common design choice. However, the performance implications of this decision are often not fully considered.

Contrary to expectations, ENUM does not provide a performance advantage. In fact, it can incur significant overhead in specific operations:

Performance Penalty with ENUM Operations:

• Querying Permitted Values: Retrieving the list of possible ENUM values requires a complex query to INFORMATION_SCHEMA, including parsing a BLOB field.
• Altering Permitted Values: Modifying the set of ENUM values requires an ALTER TABLE statement, causing table locking and potential restructuring.

Alternative Approach: Lookup Tables

Instead of using ENUM, it is preferable to employ lookup tables for representing enumerations. This approach offers several advantages:

• Faster Querying: Lookup tables allow direct and efficient retrieval of permitted values.
• Flexible Alteration: Adding or removing values is straightforward and doesn't require table modifications.

Therefore, when working with fieldsที่มี only a limited number of possible values, it is crucial to consider the performance implications of using ENUM. In such cases, alternative approaches like lookup tables provide better overall performance and flexibility.

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