# pg_rewrite

The `pg_rewrite` system catalog table stores rewrite rules for tables and views. `pg_class_internal.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_internal.oid | The table this rule is for.                                  |
| `ev_attr`    | smallint |              | 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. |