Can you explain how data version management is carried out in PostgreSQL?

In PostgreSQL, data version control is implemented through the MVCC (Multiversion Concurrency Control) mechanism. This means that when data is modified, it is not immediately overwritten; instead, new versions of rows are created. Thus, each transaction sees a consistent state of the database at the moment it started, without blocking other operations.

Example: if one transaction updates a row, another transaction that started before this update will continue to see the old version of the row until the first transaction completes. This allows efficient handling of concurrent queries and ensures transaction isolation.

For explicit data version control, additional fields such as a timestamp or version number can be used to track changes at the application level.