Vacuum and Vacuum Full POSTGRESQL

The vacuum of the PostgreSQL system is a routine maintenance process. The system will also start the autovacuum daemon when starting the service to maintain this. Of course, the vacuum command also allows users to manually perform the vacuum operation. In addition to clearing the dead tuples, vacuum also has the function of freezing the transaction ID, because now the transaction ID of PostgreSQL only supports 32 bits (about 4 billion transactions), when the transaction ID reaches the maximum value, it will start from 0 again, before this time All transactions will become “future” transactions…