Can you explain what version control means in PostgreSQL?

Version control in PostgreSQL is usually associated with the MVCC (Multiversion Concurrency Control) mechanism. This means that when data is modified, new versions of rows are created, while old versions remain accessible to other transactions until they are completed. This achieves high concurrency and transaction isolation without locking.

For example: if one transaction reads data and another modifies it, the first will see the old version, and the second will see the new one. This helps avoid conflicts and ensures data consistency.

Version control can also refer to schema version management (for example, through migrations), but in the context of PostgreSQL, it more often specifically refers to MVCC.