Also FYI - the following case results in segmentation fault:
postgres@postgres=# CREATE TABLE test_jsonb_constraints ( js text, i int, x jsonb DEFAULT JSON_QUERY(jsonb '[1,2]', '$[*]' WITH WRAPPER) CONSTRAINT test_jsonb_constraint1 CHECK (js IS JSON) CONSTRAINT test_jsonb_constraint5 CHECK (JSON_QUERY(js::jsonb, '$.mm' RETURNING char(5) OMIT QUOTES EMPTY ARRAY ON EMPTY) > 'a' COLLATE "C") CONSTRAINT test_jsonb_constraint6 CHECK (JSON_EXISTS(js::jsonb, 'strict $.a' RETURNING int TRUE ON ERROR) < 2) ); CREATE TABLE Time: 13.518 ms postgres@postgres=# INSERT INTO test_jsonb_constraints VALUES ('[]'); server closed the connection unexpectedly This probably means the server terminated abnormally before or while processing the request. The connection to the server was lost. Attempting reset: Failed. The connection to the server was lost. Attempting reset: Failed. Time: 6.858 ms @!>