PG_RELFILENODE_SIZE

The PG_RELFILENODE_SIZE system catalog provides file-level space statistics. Each record in the table corresponds to a physical file on the disk and the size of the file.

**Table 1** PG_RELFILENODE_SIZE columns
Name	Type	Description
databaseid	oid	OID of the database that the physical file belongs to If a system catalog is shared across databases, its value is 0.
tablespaceid	oid	Tablespace OID of the physical file
relfilenode	oid	Serial number of the physical file
backendid	integer	ID of the background thread that creates the physical file. Generally, the value is -1.
type	integer	Type of the physical file. The value 0 indicates a data file. The value 1 indicates an FSM file. The value 2 indicates a VM file. The value 3 indicates a BCM file. If the value greater than 4 indicates the total size of the data file and BCM file of the column in a column-store table.
filesize	bigint	Size of the physical file, in bytes.