Database Reference
In-Depth Information
Figure 16.4
Users Can Create
Their Own
Datatypes, also
Called Object,
Array, or Table
Types.
LECTION type was created as a user-defined datatype using the CREATE
TYPE command. The results are shown in Figure 16.4.
SET LINESIZE 100
DESC ARTIST
DESC INSTRUMENTSCOLLECTION
The INSTRUMENTSCOLLECTION datatype is a VARRAY or fixed-
length array that can hold up to 10 values with the datatype of
VARCHAR2(32).
Now that we have looked at simple user-definable datatypes, let's look in
more detail at object collection datatypes.
16.2.4
Object Collection Datatypes
An object collection is a referenced set of elements contained within an
array. These arrays can be fixed length, dynamic, or indexed dynamic. A
dynamic array is an array where the number of array iterations is undeter-
mined. Therefore, a dynamic array is essentially a pointer. Object collection
datatypes are shown in Table 16.4.
Let's look at some examples, beginning with the simplest to use,
VARRAY collections.
