Examine the code snippet from the declarative section of a PL/SQL block:
DECLARE
TYPE va1 IS VARRAY(10) OF VARCHAR2(20);
SUBTYPE scale IS NUMBER(1,0);
TYPE tb1 IS TABLE OF departments.department_name%TYPE INDEX BY
departments.department_id%TYPE;
TYPE tb2 IS TABLE OF va1 INDEX BY PLS_INTEGER;
TYPE tb3 IS TABLE OF scale INDEX BY VARCHAR2(10);
TYPE tb4 IS TABLE OF DATE INDEX BY DATE;
TYPE tb5 IS TABLE OF NUMBER INDEX BY CHAR(2);
….
Which of the above are valid definitions for associative arrays? (Choose all that apply.)
A.
tb1
B.
tb2
C.
tb3
D.
tb4
E.
tb5
B, C