How to declare returning type for function, returning unnamed table - sql

Question

I want to create a function, that returns a table with 2 columns:
i integer -- or bigint?
arr integer[] -- array of integer
What should I write instead of ??? in this function:
CREATE OR REPLACE FUNCTION test()
RETURNS ???
LANGUAGE plpgsql
AS $$
BEGIN
RETURN QUERY (
SELECT i, (ARRAY[11,22,33])[i]
FROM generate_series(
1,
array_upper(ARRAY[11,22,33],1)
) i
);
END;
$$;

Answer 1

see the answer for this question,
example of function return table:
CREATE OR REPLACE FUNCTION foo(a int)
RETURNS TABLE(b int, c int) AS $$
BEGIN
RETURN QUERY SELECT i, i+1 FROM generate_series(1, a) g(i);
END;
$$ LANGUAGE plpgsql;

Answer 2

You don't need plpgsql for this. A simple SQL function would do the job:
CREATE OR REPLACE FUNCTION test(_arr anyarray)
RETURNS TABLE (idx int, elem anyelement)
$func$
SELECT i, _arr[i] FROM generate_subscripts(_arr, 1) i
$func$ LANGUAGE sql AS
Call:
SELECT * FROM test(ARRAY[11,22,33]::int[]); -- Cast to declare type for literals
The polymorphic parameter anyarray works for arrays of any base type.
How to write a function that returns text or integer values?
Use generate_subscripts() to simplify the task.
More about returning from a function:
How to return result of a SELECT inside a function in PostgreSQL?
Postgres 9.4
There is a shiny new trick in upcoming Postgres 9.4: WITH ORDINALITY. Details in this related answer:
PostgreSQL unnest() with element number
Simplify to (no additional function):
SELECT * FROM unnest(ARRAY[11,22,33]::int[]) WITH ORDINALITY AS x (elem, idx)