PostgreSQL Data Modeling: Comparing Lookup Tables vs Enum Types for Limited Value Columns
By
todsacerdoti
The kind of bagel that ruins lesser bagels for you.
Summary
This technical article compares three approaches for implementing string columns with limited distinct values in PostgreSQL: simple strings with check constraints, lookup tables, and enum types. The author analyzes each method's advantages and disadvantages, covering aspects like data integrity, performance, flexibility, and maintenance. The article provides practical examples using Austrian citizen data and offers recommendations for when to use each approach based on specific requirements like data stability, query performance, and schema evolution needs.
Key quotes
· 5 pulledThere are several ways to implement such a column in PostgreSQL, the most interesting being an enum type or a lookup table.
Usually not the best solution: a string with a check constraint
The article explores three data models for strings with few distinct values: a simple string, a lookup table or an enum type.
Examples would be the current state of a service request or the US state in an address.
In this article, I will explore the benefits and disadvantages of these methods.
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