PL/SQL Datatype PART 2

LOB Types
The LOB (large object) datatypes BFILE, BLOB, CLOB, and NCLOB let you store blocks of unstructured data (such as text, graphic images, video clips, and sound waveforms) up to four gigabytes in size. And, they allow efficient, random, piece-wise access to the data.

BFILE
You use the BFILE datatype to store large binary objects in operating system files outside the database. Every BFILE variable stores a file locator, which points to a large binary file on the server. BFILEs are read-only.

BLOB
You use the BLOB datatype to store large binary objects in the database, in-line or out-of-line. Every BLOB variable stores a locator, which points to a large binary object. BLOBs participate fully in transactions, are recoverable, and can be replicated. Changes made by package DBMS_LOB can be committed or rolled back.

CLOB
You use the CLOB datatype to store large blocks of character data in the database.

NCLOB
You use the NCLOB datatype to store large blocks of NCHAR data in the database.

Maximun size for all LOB's cannot exceed 4GB.

BOOLEAN
You use the BOOLEAN datatype to store the logical values TRUE, FALSE, and NULL . Only logic operations are allowed on BOOLEAN variables. You cannot insert the values TRUE and FALSE into a database column. Also, you cannot select or fetch column values into a BOOLEAN variable.