create table perso.json_data(id number, data_val blob);

insert into perso.json_data 

values(
1,
utl_raw.cast_to_raw('{"class":[{"class_type":"ownership","values":[{"nm":"id","value":"1"}]},{"class_type":"country","values":[{"nm":"id","value":"640"}]},{"class_type":"features","values":[{"nm":"id","value":"15"},{"nm":"id","value":"20"}]}]}')
);


insert into perso.json_data values(
2,
utl_raw.cast_to_raw('{"class":[{"class_type":"ownership","values":[{"nm":"id","value":"18"}]},{"class_type":"country","values":[{"nm":"id","value":"11"}]},{"class_type":"features","values":[{"nm":"id","value":"7"},{"nm":"id","value":"640"}]}]}')
)
;

commit;


ALTER TABLE perso.json_data
ADD CONSTRAINT check_is_json
 CHECK (data_val IS JSON (STRICT));
 
 CREATE INDEX perso.json_data_idx ON json_data (data_val)
 INDEXTYPE IS CTXSYS.CONTEXT
 PARAMETERS ('section group CTXSYS.JSON_SECTION_GROUP SYNC (ON COMMIT)');


select *
from perso.json_data

where ctxsys.contains(data_val, '(640 INPATH(/class/values/value)) and (country inpath (/class/class_type))')>0

{
         "class":[
                  {
                   "class_type":"ownership",
                   "values":[{"nm":"id","value":"1"}]
                  },
                  {
                   "class_type":"country",
                   "values":[{"nm":"id","value":"640"}]
                  },
                  ,
                  {
                   "class_type":"features",
                   "values":[{"nm":"id","value":"15"},{"nm":"id","value":"20"}]
                  }
                 ]
        }

{
         "class":[
                  {
                   "class_type":"ownership",
                   "values":[{"nm":"id","value":"18"}]
                  },
                  {
                   "class_type":"country",
                   "values":[{"nm":"id","value":"11"}]
                  },
                  ,
                  {
                   "class_type":"features",
                   "values":[{"nm":"id","value":"7"},{"nm":"id","value":"640"}]
                  }
                 ]
        }