The gp_persistent_relfile_node table keeps track of the status of file system objects in relation to the transaction status of database objects. This information is used to make sure the state of the system catalogs and the file system files persisted to disk are synchronized.

Table 1. pg_catalog.gp_persistent_relfile_node

column type references description
tablespace_oid oid pg_tablespace.oid Tablespace object id
database_oid oid pg_database.oid Database object id
relfilenode_oid oid pg_class.relfilenode The object id of the relation file node.
segment_file_num integer    
relation_storage_manager smallint    
persistent_state smallint   0 - free

1 - create pending

2 - created

3 - drop pending

4 - aborting create

5 - “Just in Time” create pending

6 - bulk load create pending

relation_bufpool_kind integer    
parent_xid integer   Global transaction id.
persistent_serial_num bigint   Log sequence number position in the transaction log for a file block.
previous_free_tid tid   Used by HAWQ to internally manage persistent representations of file system objects.