declare 
  TYPE matrix_risk_obj IS RECORD (vector1 VARCHAR2(5), vector2 VARCHAR2(5), vector3 VARCHAR2(5), risk VARCHAR2(5)); 
  TYPE matrix_risk_tab IS TABLE OF matrix_risk_obj;
  v_a matrix_risk_tab := matrix_risk_tab();
begin
  v_a.extend;
  v_a(1).vector1 := 'A';
  v_a(1).vector2 := 'B';
  v_a(1).vector3 := 'C';
  v_a(1).risk    := 'D';
end;
/

SQL> CREATE OR REPLACE
  2    TYPE MATRIX_RISK_OBJ
  3      IS OBJECT(
  4                VECTOR1 VARCHAR2(5),
  5                VECTOR2 VARCHAR2(5),
  6                VECTOR3 VARCHAR2(5),
  7                RISK VARCHAR2(5)
  8               )
  9  /

Type created.

SQL> BEGIN
  2      DBMS_OUTPUT.PUT_LINE(MATRIX_RISK_OBJ('A','B','C','D').RISK);
  3  END;
  4  /
D

PL/SQL procedure successfully completed.

SQL> DECLARE
  2      TYPE MATRIX_RISK_REC
  3        IS RECORD(
  4                  VECTOR1 VARCHAR2(5),
  5                  VECTOR2 VARCHAR2(5),
  6                  VECTOR3 VARCHAR2(5),
  7                  RISK VARCHAR2(5)
  8                 );
  9      V_REC MATRIX_RISK_REC;
 10  BEGIN
 11      DBMS_OUTPUT.PUT_LINE('RISK = "' || V_REC.RISK || '"');
 12      DBMS_OUTPUT.PUT_LINE('RISK = "' || MATRIX_RISK_REC().RISK || '"');
 13      DBMS_OUTPUT.PUT_LINE('RISK = "' || MATRIX_RISK_REC('A','B','C',NULL).RISK || '"');
 14  END;
 15  /
RISK = ""
RISK = ""
RISK = ""

PL/SQL procedure successfully completed.

SQL>

select * into record/object ... ?

SQL> SELECT  BANNER
  2    FROM  V$VERSION
  3  /

BANNER
----------------------------------------------------------------
Oracle Database 10g Enterprise Edition Release 10.2.0.5.0 - 64bi
PL/SQL Release 10.2.0.5.0 - Production
CORE    10.2.0.5.0      Production
TNS for 64-bit Windows: Version 10.2.0.5.0 - Production
NLSRTL Version 10.2.0.5.0 - Production

SQL> DECLARE
  2      TYPE MATRIX_RISK_REC
  3        IS RECORD(
  4                  VECTOR1 VARCHAR2(5),
  5                  VECTOR2 VARCHAR2(5),
  6                  VECTOR3 VARCHAR2(5),
  7                  RISK VARCHAR2(5)
  8                 );
  9      TYPE MATRIX_RISK_TAB
 10        IS TABLE OF MATRIX_RISK_REC;
 11      V_REC_TBL MATRIX_RISK_TAB;
 12  BEGIN
 13      SELECT  'A',
 14              'B',
 15              'C',
 16              'D'
 17        BULK  COLLECT
 18        INTO  V_REC_TBL
 19        FROM  DUAL;
 20  END;
 21  /

PL/SQL procedure successfully completed.

SQL> 

DECLARE
    TYPE MATRIX_RISK_REC
      IS RECORD(
                VECTOR1 VARCHAR2(5),
                VECTOR2 VARCHAR2(5),
                VECTOR3 VARCHAR2(5),
                RISK VARCHAR2(5)
               );
    TYPE MATRIX_RISK_TAB
      IS TABLE OF MATRIX_RISK_REC;
    V_REC_TBL MATRIX_RISK_TAB := MATRIX_RISK_TAB(); -- a) инициализирует коллекцию
BEGIN
    V_REC_TBL.EXTEND; -- б) extend коллекцию что "в одном флаконе" создает и инициализирует (конструктор) RECORD (все атрибуты инициализуются в NULL)
    DBMS_OUTPUT.PUT_LINE('RISK = "' || V_REC_TBL(1).RISK || '"');
END;
/
RISK = ""

PL/SQL procedure successfully completed.

SQL>