Let's suppose I have a parent table and another table that inherits from it in PostgreSQL 9.5. And then if I add an index to the parent table how do I make it propagated to the inheriting table?

Example:

CREATE TABLE parent (
  id serial,
  data text
);

CREATE TABLE child (
  stuff text
) INHERITS (parent);

CREATE INDEX ix_parent_data ON parent(data);

http://sqlfiddle.com/#!17/05ea2/1

Important note - the table is already created without INCLUDING clause.