The (distant) PostgreSQL 9.5 release is expected to have a new row-level
security feature. This
article from Michael Paquier describes how to make use of it.
"This row control mechanism is controlled using a new query called
CREATE POLICY (of course its flavor ALTER POLICY to update an existing
policy and DROP POLICY to remove a policy exist as well). By default,
tables have no restrictions in terms of how rows can be added and
manipulated. However they can be made able to accept level restriction
policies using ALTER TABLE and ENABLE ROW LEVEL SECURITY."