pg_rewrite
   The catalog pg_rewrite stores rewrite rules for tables and views.
  
Table 52.44. pg_rewrite Columns
| Name | Type | References | Description | 
|---|---|---|---|
| oid | oid | Row identifier (hidden attribute; must be explicitly selected) | |
| rulename | name | Rule name | |
| ev_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 modes
       the rule fires. O= rule fires in “origin” and “local” modes,D= rule is disabled,R= rule fires in “replica” mode,A= rule fires always. | |
| is_instead | bool | True if the rule is an INSTEADrule | |
| 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 | 
    pg_class.relhasrules
    must be true if a table has any rules in this catalog.