CREATE EXTENSION multicorn;
CREATE server multicorn_srv foreign data wrapper multicorn options (
    wrapper 'multicorn.testfdw.TestForeignDataWrapper'
);
CREATE user mapping for postgres server multicorn_srv options (usermapping 'test');
CREATE foreign table testmulticorn (
    test1 character varying[],
    test2 character varying[]
) server multicorn_srv options (
    option1 'option1',
    test_type 'list'
);
-- Test "normal" usage
select * from testmulticorn;
NOTICE:  {'test_type': 'list', 'usermapping': 'test', 'option1': 'option1'}
NOTICE:  ['test1', 'test2']
NOTICE:  []
NOTICE:  set(['test1', 'test2'])
    test1     |    test2     
--------------+--------------
 {test1,1,0}  | {test2,2,0}
 {test1,3,1}  | {test2,1,1}
 {test1,2,2}  | {test2,3,2}
 {test1,1,3}  | {test2,2,3}
 {test1,3,4}  | {test2,1,4}
 {test1,2,5}  | {test2,3,5}
 {test1,1,6}  | {test2,2,6}
 {test1,3,7}  | {test2,1,7}
 {test1,2,8}  | {test2,3,8}
 {test1,1,9}  | {test2,2,9}
 {test1,3,10} | {test2,1,10}
 {test1,2,11} | {test2,3,11}
 {test1,1,12} | {test2,2,12}
 {test1,3,13} | {test2,1,13}
 {test1,2,14} | {test2,3,14}
 {test1,1,15} | {test2,2,15}
 {test1,3,16} | {test2,1,16}
 {test1,2,17} | {test2,3,17}
 {test1,1,18} | {test2,2,18}
 {test1,3,19} | {test2,1,19}
(20 rows)

select test1[2] from testmulticorn;
NOTICE:  []
NOTICE:  set(['test1'])
 test1 
-------
 1
 3
 2
 1
 3
 2
 1
 3
 2
 1
 3
 2
 1
 3
 2
 1
 3
 2
 1
 3
(20 rows)

DROP EXTENSION multicorn cascade;
NOTICE:  drop cascades to 3 other objects
DETAIL:  drop cascades to server multicorn_srv
drop cascades to user mapping for postgres
drop cascades to foreign table testmulticorn