common_schema をインストールできます 。そうすれば、次のようなことができるはずです:
select common_schema.extract_json_value(d.table1,'/multicast_id') as multicase_id,
common_schema.extract_json_value(d.table1,'/success') as success,
common_schema.extract_json_value(d.table1,'/failure') as failure,
common_schema.extract_json_value(d.table1,'/canonical_ids') as canonical_ids,
common_schema.extract_json_value(d.table1,'/results') as results,
common_schema.extract_json_value(d.table1,'/message_id') as message_id
from database d;