The pg_inherits system catalog table records information about table inheritance hierarchies. There is one entry for each direct child table in the database. (Indirect inheritance can be determined by following chains of entries.) In HAWQ, inheritance relationships are created by both the INHERITS clause (standalone inheritance) and the PARTITION BY clause (partitioned child table inheritance) of CREATE TABLE.

Table 1. pg_catalog.pg_inherits

column type references description
inhrelid oid pg_class.oid The OID of the child table.
inhparent oid pg_class.oid The OID of the parent table.
inhseqno integer   If there is more than one direct parent for a child table (multiple inheritance), this number tells the order in which the inherited columns are to be arranged. The count starts at 1.