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In PostgreSQL, a generated column is a special type of column whose values are automatically calculated based on expressions or values from other columns. A generated column is referred to as a computed column in the SQL Server or a virtual column in Oracle .

There are two kinds of generated columns: Stored: A stored generated column is calculated when it is inserted or updated and occupies storage space. Virtual: A virtual generated column is computed when it is read and does not occupy storage space.

A virtual generated column is like a view, whereas a stored generated column is similar to a materialized view. Unlike a material view, PostgreSQL automatically updates data for stored generated columns.

PostgreSQL currently implements only stored generated columns.