test=> \c test postgres
You are now connected to database test as user postgres.
test=# create user vst;
CREATE USER
test=# create table test(id int, name text);
CREATE TABLE
test=# create view test_view AS SELECT * FROM test WHERE id >  10 ;
CREATE VIEW
test=# insert into test(id, name) values( 1 , 'first');
INSERT  2392670   1 
test=# insert into test(id, name) values( 2 , 'second');
INSERT  2392671   1 
test=# insert into test(id, name) values( 12 , 'for view');
INSERT  2392672   1 
test=# grant select on test_view to vst;
GRANT
test=# grant update, delete on test to vst;
GRANT
test=# \c test vst
You are now connected to database test as user vst.
test=> select * from test_view;
 id |   name
 ----+----------
 
  12  | for view
( 1  row)

test=> select * from test;
ERROR:  test: permission denied
test=> update test set name='newname';
UPDATE  3 
test=> update test set name='newname' where id= 12 ;
ERROR:  test: permission denied

test=> \c test postgres
You are now connected to database test as user postgres.
test=# revoke update, delete on test from vst;
REVOKE
test=# create OR REPLACE  rule r_test_upd as on update to test_view do instead
test-# update test set id=new.id, name=new.name where id=old.id;
CREATE RULE
test=# alter table test alter column id set not null;
ALTER TABLE
test=# alter table test add constraint pk_test_id primary key(id);
NOTICE:  ALTER TABLE / ADD PRIMARY KEY will create implicit index 'pk_test_id' for table 'test'
ALTER TABLE
test=# create OR REPLACE  rule r_test_del as on delete to test_view do instead
test-# delete from test where id=old.id;
CREATE RULE
test=# \c test vst
You are now connected to database test as user vst.
test=> insert into test_view(id, name) values( 15 , '15');
INSERT  2392678   1 

test=> create sequence seq_test_id;
CREATE SEQUENCE
test=> \c test postgres
You are now connected to database test as user postgres.
test=# alter table test alter column id set default nextval('seq_test_id');
ALTER TABLE
test=# select setval('seq_test_id',  20 );
 setval
 --------
 
      20 
( 1  row)
test=# alter table test alter column name set default 'default name';
ALTER TABLE
test=# insert into test_view(id) select nextval('seq_test_id');;
INSERT  2392686   1 
test=# insert into test_view(name) values('21');
ERROR:  ExecInsert: Fail to add null value in not null attribute id
test=# select * from test;
 id |  name
 ----+---------
 
   1  | newname
   2  | newname
  12  | newname
  15  |  15 
  21  |
( 5  rows)

test=# alter table test_view alter name set default 'default name from view';
ALTER TABLE
test=# insert into test_view(id) select nextval('seq_test_id');
INSERT  2392707   1 
test=# select * from test_view;
 id |          name
 ----+------------------------
 
  12  | newname
  15  |  15 
  16  |  16 
  21  |
  22  |
  23  | default name from view
( 6  rows)

test=# alter table test_view alter id set default nextval('seq_test_id');
ALTER TABLE
test=# insert into test_view(name) select nextval('ins name');
ERROR:  nextval: invalid name syntax

test=# \d test_view
                 View "public.test_view"
 Column |  Type   |              Modifiers
 --------+---------+--------------------------------------
 
 id     | integer | default nextval('seq_test_id'::text)
 name   | text    | default 'default name from view'
View definition: SELECT test.id, test.name FROM test WHERE (test.id >  10 );
Rules: r_test_ins,
       r_test_upd,
       r_test_del

test=# insert into test_view(name) values('new ins name');
INSERT  2393020   1 

test=# create or replace rule r_test_ins AS on insert to test_view do instead   
test-# insert into test (id,name) select case when new.id is null then 
test-# nextval('seq_test_id') else new.id end, case when new.name is null
test-# then 'default view name' else new.name end;
CREATE RULE
test=# insert into test_view(name) values('test');
INSERT  2397669   1 

test=# \c test vst
You are now connected to database test as user vst.
test=> create table test2(id integer, name varchar( 30 ));
CREATE TABLE
test=> create view test2_view as select * from test2;
CREATE VIEW
test=> create or replace rule r_test2_ins as on insert to test2_view do instead
test-> insert into test2(id, name) values(new.id, new.name);
CREATE RULE
test=> \c test postgres
You are now connected to database test as user postgres.
test=# create user secretarsha;
CREATE USER
test=# \c test vst
You are now connected to database test as user vst.
test=> grant select, insert on test2_view to secretarsha;
GRANT
test=> \c test secretarsha
You are now connected to database test as user secretarsha.
test=> select * from test2_view;
 id | name
 ----+------
 
( 0  rows)

test=> insert into test2_view values( 1 , 'test1');
INSERT  2397682   1 
test=> select * from test2_view;
 id | name
 ----+-------
 
   1  | test1
( 1  row)

test=> create view my_view as select * from test2_view;
CREATE VIEW
test=> create rule r_my_ins as on insert to my_view do instead insert into test2_view(id, name) values(new.id, new.name);
CREATE RULE
test=> grant insert, select on my_view to public;
GRANT
test=> insert into my_view values( 2 , '2name');
INSERT  2397687   1 
test=> select * from test2_view;     
 id | name
 ----+-------
 
   1  | test1
   2  | 2name
( 2  rows)

test=> \c test postgres
You are now connected to database test as user postgres.
test=# create user someone;
CREATE USER
test=# \c test someone
You are now connected to database test as user someone.
test=> select * from my_view;
 id | name
 ----+-------
 
   1  | test1
   2  | 2name
( 2  rows)

test=> insert into my_view(id, name) values( 3 , 'test 3');
INSERT  2397688   1 
test=> select * from my_view;
 id |  name
 ----+--------
 
   1  | test1
   2  | 2name
   3  | test  3 
( 3  rows)