The RAW datatype allows you to store and manipulate relatively small amounts of binary data. Unlike the case with VARCHAR2 and other character types, RAW data never undergoes any kind of character set conversion when traveling back and forth between your PL/SQL programs and the database. RAW variables are declared as follows:
The value for maximum_size may range from 1 through 32767. Be aware that while a RAW PL/SQL variable can hold up to 32,767 bytes of data, a RAW database column can hold only 2,000 bytes.
RAW is not a type that you will use or encounter very often. It’s useful mainly when you need to deal with small amounts of binary data. When dealing with the large amounts of binary data found in images, sound files, and the like, you should look into using the BLOB (binary large object) type. BLOB is described later in this chapter (see Working with LOBs).