create table test (data jsonb);
insert into test (data) values ('{"id": 1, "items":[{"a": 1, "b": 2}, {"a":3, "b": 4}]}');
insert into test (data) values ('{"id": 2, "items":[{"a": 2, "b": 3}, {"a":4, "b": 5}]}');
select * from test;
                           data
----------------------------------------------------------
 {"id": 1, "items": [{"a": 1, "b": 2}, {"a": 3, "b": 4}]}
 {"id": 2, "items": [{"a": 2, "b": 3}, {"a": 4, "b": 5}]}
(2 rows)

Looking for:

id | a | b
----------
1  | 1 | 2
1  | 3 | 4
2  | 2 | 3
2  | 4 | 5

Ideally creating a view into the db.