pg_rewrite

The pg_rewrite system catalog table stores rewrite rules for tables and views. pg_class.relhasrules must be true if a table has any rules in this catalog.

Table 1. pg_catalog.pg_rewrite

column	type	references	description
oid	oid		The object ID
rulename	name		Rule name
ev_class	oid	pg_class.oid	The table this rule is for
ev_type	char		Event type that the rule is for: 1 = SELECT, 2 = UPDATE, 3 = INSERT, 4 = DELETE
ev_enabled	char		Controls in which session replication role mode the rule fires. Always O, rule fires in origin mode.
is_instead	boolean		True if the rule is an INSTEAD rule
ev_qual	pg_node_tree		Expression tree (in the form of a nodeToString() representation) for the rule’s qualifying condition
ev_action	pg_node_tree		Query tree (in the form of a nodeToString() representation) for the rule’s action