SQL query - Do I need a full join to produce this combined result?
I don't use amazon-presto, but I'm wondering if you could adapt this SQL Server solution to your needs.

--demo setup
drop table if exists table1;
drop table if exists table2;
CREATE TABLE Table1
    (id int, time int, x int)
;

INSERT INTO Table1
    (id, time, x)
VALUES
    (1, 1, 1),
    (1, 2, 2)
;


CREATE TABLE Table2
    (id int, time int, y int, z int)
;

INSERT INTO Table2
    (id, time, y, z)
VALUES
    (1, 2, 2, 2),
    (1, 3, 3, 3)
;

------------------
--solution
;with cte as
(
select id, time from Table1
union
select id, time from Table2
)
SELECT c.id, c.TIME, t1.x, t2.y, t2.z
FROM cte c
LEFT JOIN table1 t1
    ON t1.id = c.id
        AND t1.TIME = c.TIME
LEFT JOIN table2 t2
    ON t2.id = c.id
        AND t2.TIME = c.TIME;




| id | TIME | x    | y    | z    |
|----|------|------|------|------|
| 1  | 1    | 1    | NULL | NULL |
| 1  | 2    | 2    | 2    | 2    |
| 1  | 3    | NULL | 3    | 3    |