|Oracle® Database SecureFiles and Large Objects Developer's Guide
11g Release 2 (11.2)
Part Number E18294-01
A Large Object datatype that is a binary file residing in the file system, outside of the database data files and tablespace. Note that the
BFILE datatype is also referred to as an external LOB in some documentation.
Binary Large Object (BLOB)
A Large Object datatype that has content consisting of binary data and is typically used to hold unstructured data. The
BLOB datatype is included in the category Persistent LOBs because it resides in the database.
Character Large Object (CLOB)
The LOB datatype that has content consisting of character data in the database character set. A CLOB can be indexed and searched by the Oracle Text search engine.
Deduplication enables Oracle Database to automatically detect duplicate LOB data and conserve space by only storing one copy (if storage parameter is
A Large Object datatype that is stored outside of the database tablespace. The
BFILE datatype is the only external LOB datatype. See also
internal persistent LOB
A large object (LOB) that is stored in the database in a
Large Objects (LOBs)
Large Objects include the following SQL datatypes:
BFILE. These datatypes are designed for storing data that is large in size. See also
BFILE, Binary Large Object, Character Large Object, and National Character Large Object.
A large object datatype that is a field of an object datatype. For example a
CLOB field of an object type.
The actual data stored by the Large Object. For example, if a
BLOB stores a picture, then the value of the
BLOB is the data that makes up the image.
National Character Large Object
The LOB datatype that has content consisting of Unicode character data in the database national character set. An
NCLOB can be indexed and searched by the Oracle Text search engine.
NCLOB that is stored in the database. A persistent LOB instance can be selected out of a table and used within the scope of your application. The ACID (atomic, consistent, isolated, durable) properties of the instance are maintained just as for any other column type. Persistent LOBs are sometimes also referred to as internal persistent LOBs or just, internal LOBs.
A persistent LOB can exist as a field of an object datatype and an instance in a LOB-type column. For example a
CLOB attribute of an instance of type
See also temporary LOB and external LOB.
LOB storage parameter that allows deduplication, encryption, and compression. The opposite parameter, that does not allow these features, is