Implicit rule created for materialized views

Hi

In playing with materialized views, I noticed that they still seem to
have an _RETURN rule implicitly created like a regular view. This
doesn't seem right to me - is there a reason?

viper:~ dpage$ /usr/local/pgsql-9.3/bin/psql -p 5433 -U postgres
psql (9.3beta1)
Type "help" for help.

postgres=# CREATE MATERIALIZED VIEW ruletest AS SELECT * FROM pg_class;
SELECT 298
postgres=# SELECT pg_get_ruledef(oid) FROM pg_rewrite WHERE ev_class =
'ruletest'::regclass;                        pg_get_ruledef
-----------------------------------------------------------------CREATE RULE "_RETURN" AS
       +    ON SELECT TO ruletest DO INSTEAD  SELECT pg_class.relname, +    pg_class.relnamespace,
              +    pg_class.reltype,                                          +    pg_class.reloftype,
                     +    pg_class.relowner,                                         +    pg_class.relam,
                            +    pg_class.relfilenode,                                      +
pg_class.reltablespace,                                   +    pg_class.relpages,
 +    pg_class.reltuples,                                        +    pg_class.relallvisible,
        +    pg_class.reltoastrelid,                                    +    pg_class.reltoastidxid,
               +    pg_class.relhasindex,                                      +    pg_class.relisshared,
                      +    pg_class.relpersistence,                                   +    pg_class.relkind,
                             +    pg_class.relnatts,                                         +    pg_class.relchecks,
                                    +    pg_class.relhasoids,                                       +
pg_class.relhaspkey,                                      +    pg_class.relhasrules,
 +    pg_class.relhastriggers,                                   +    pg_class.relhassubclass,
        +    pg_class.relispopulated,                                   +    pg_class.relfrozenxid,
               +    pg_class.relminmxid,                                       +    pg_class.relacl,
                      +    pg_class.reloptions                                        +   FROM pg_class;
 
(1 row)


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Dave Page
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