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
`rulename`	name		Rule name.
`ev_class`	oid	pg_class.oid	The table this rule is for.
`ev_attr`	int2		The column this rule is for (currently, always zero to indicate the whole table).
`ev_type`	char		Event type that the rule is for: 1 = SELECT, 2 = UPDATE, 3 = INSERT, 4 = DELETE.
`is_instead`	boolean		True if the rule is an INSTEAD rule.
`ev_qual`	text		Expression tree (in the form of a `nodeToString()` representation) for the rule's qualifying condition.
`ev_action`	text		Query tree (in the form of a `nodeToString()` representation) for the rule's action.