Chapter 2. PostgreSQL Data Types

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Data types are the basic building blocks of any RDBMS. They provide the mechanisms needed for the higher-level functionality of modern databases to exist. Queries, data validation, comparison operators, manipulation functions, and so on exist only as an extension of the data-type concept.

Without data types, it would be extremely difficult to consistently obtain meaningful information from a database. Data types ensure that data at the columnar level is stored in a consistent format. This facilitates the capability to make comparisons and manipulation of the underlying data in a predictable manner. Without such consistency, it could be like comparing apples and oranges (or integers and strings, in this case) when trying to make valid comparisons of the underlying data.

A further benefit of data types is that they provide a significant boost to the overall performance and efficiency of a database system. Because the database knows what type of data is stored in a given column, assumptions can be made about how to most efficiently store and retrieve that data.

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