Description: A virtual column is a column that is not physically stored in a database but is dynamically calculated from other existing columns. This type of column allows developers and database administrators to perform calculations, transformations, or concatenations of data without the need to duplicate information in storage. Virtual columns are particularly useful for optimizing disk space usage and improving query efficiency, as they are generated in real-time when accessing data. Additionally, they can simplify query logic by allowing users to access derived data without having to perform manual calculations. In terms of performance, virtual columns may be slower than physical columns in certain circumstances, as they require additional processing at query time. However, their proper use can lead to better data organization and greater flexibility in data manipulation, making them a valuable tool in the design of relational databases.
