delete update where 1=1 not work

[se7enshidb]

postgres=# update t_sales set prod='c';
ERROR: UPDATE requires a WHERE clause
postgres=# update t_sales set prod='c' where 1=1;
UPDATE 6
postgres=# delete from t_sales ;
ERROR: DELETE requires a WHERE clause
postgres=# update t_sales set prod='c';
ERROR: UPDATE requires a WHERE clause
postgres=# update t_sales set prod='c' where 1=1;
UPDATE 6
postgres=# delete from t_sales where 1=1;
DELETE 6

[eradman]

The examples you provided appear to work. Which result is incorrect?