create type test_type as object (test ineteger) ;
create type test_type_indexby as table of test_type index by binary_integer;

SQL> drop type test_type;

Type dropped.

SQL> create type test_type as object (test integer) ;
  2  /

Type created.

SQL> drop type test_type_indexby;

Type dropped.

SQL> create type test_type_indexby as table of test_type index by binary_integer;
  2  /

Warning: Type created with compilation errors.

SQL>

SQL> show error
Errors for TYPE TEST_TYPE_INDEXBY:
LINE/COL ERROR
-------- -----------------------------------------------------------------
0/0      PL/SQL: Compilation unit analysis terminated
1/27     PLS-00355: use of pl/sql table not allowed in this context