Which two statements are true about associative arrays and varrays? (Choose two.)
A.
Only varrays must use sequential numbers as subscripts.
B.
Only varrays can be used as column types in database tables.
C.
Both associative arrays and varrays must use sequential numbers as subscripts.
D.
Both associative arrays and varrays can be used as column types in database tables.
AB
http://docs.oracle.com/cd/E11882_01/appdev.112/e25519/composites.htm#LNPLS443
A. true
Varrays (Variable-Size Arrays)
To access an element of a varray variable, use the syntax variable_name(index).
The lower bound of index is 1; the upper bound is the current number of elements.
A varray is appropriate when:
You know the maximum number of elements.
You usually access the elements sequentially.
Associative array
Each key is a unique index, used to locate the associated value with the syntax variable_name(index).
The data type of index can be either a string type or PLS_INTEGER.
B. true
Varrays (Variable-Size Arrays)
If a varray variable is less than 4 KB, it resides inside the table of which it is a column;
otherwise, it resides outside the table but in the same tablespace.
same as 12