Hot physical backup is an important capability for databases.
Physical backup allows us to get a completely consistent view of all database changes at once. Physical backup also allows us to backup even while DDL changes are being executed on the database. Apart from resource constraints, there is no additional overhead or locking with this approach.
Physical backup procedures are slightly more complex than logical backup procedures. So, let's start with a simple procedure to produce a standalone backup.
The following steps assume that a number of environment variables have been set:
$PGDATAis the path to the PostgreSQL data directory, ending with
$BACKUPNAMEis the filename of a backup file ...