Prentice Hall Oracle Plsql By Example 3Rd Edition [Electronic resources] نسخه متنی

1)

A

2)

C

You will recall that a following is always used in an index-by table declaration

INDEX BY BINARY_INTEGER;

3)

A

A nested table is automatically NULL when it is declared. As a result, it must be initialized prior to its use.

4)

C

If a PL/SQL table contains only one element, it is its first and last element. As a result, the FIRST method returns the subscript of the first element, 1, and the LAST method returns the subscript of the last element, 1.

5)

C

It is important to remember that a PL/SQL table in this case is a nested table. You will recall that the DELETE method cannot be used with a nested table.

1)

A

You will recall that using a DELETE method on varrays causes a syntax error because varrays are dense.

2)

B

A varray can contain a number of elements, varying from zero (empty array) to its maximum size. In other words, an upper bond of the array can be extended to its maximum size.

3)

A

4)

C

The COUNT method returns the current number of varray elements, and the LIMIT method returns the maximum number of elements that a varray can contain.

5)

D

Because varrays cannot be sparse, a DELETE method causes a syntax error when it is issued against a varray.

1)

A

2)

B

Regardless of its element type, an upper bound of a varray can be extended to its maximum size.

3)

B

A nested table must be initialized prior to its use regardless its element data type.

4)

C

Consider the statement

varray2(2)(3)

In this statement you are referencing the second element of varray2 and third element of varray1. Each element of varray2 is a varray of three integers defined as varray1. Recall the following declaration statement:

varray2 varray_type2 :=
varray_type2(varray1, varray_type1
(4, 5, 6));

where varray_type1(4, 5, 6) is the second element of the varray2. Notice that the third element of varray1 is 6. As a result, the variable var1 is assigned a value of 6.

5)

B

You will recall that the PL/SQL block contains the following statements:

varray2.EXTEND;
varray2(3) := varray_type1(0);
varray2(3).EXTEND;

The first statement increases the size of the varray2. In other words, this statement adds the third element to the collection. The second statement initializes the third element of the varray2 via constructor associated with the varray type varray_type1. This is done because each element of the varray2 is a varray of three integers. This adds one element to the varray1. The third statement increases the size of the varray1 by adding a placeholder for the second element. In other words, it adds the second element to the third element of varray2.