Other Datatypes
Aside from the basic character, number, and date datatypes, Oracle supports a number
of specialized datatypes:
RAW and LONG RAW
Normally, your Oracle database not only stores data but also interprets it. When
data is requested or exported from the database, the Oracle database sometimes
massages the requested data. For instance, when you dump the values from a
NUMBER column, the values written to the dump file are the representations of
the numbers, not the internally stored numbers.
The RAW and LONG RAW datatypes circumvent any interpretation on the part
of the Oracle database. When youspecify one of these datatypes, Oracle will
store the data as the exact series of bits presented to it. The RAW datatypes typically
store objects with their own internal format, such as bitmaps. A RAW
datatype can hold 2 KB, while a LONG RAW datatype can hold 2 GB.
ROWID
The ROWID is a special type of column known as a pseudocolumn. The ROWID
pseudocolumn can be accessed just like a column in a SQL SELECT statement.
There is a ROWID pseudocolumn for every row in an Oracle database.
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