CLOB and BLOB data types

You can store a smart large object directly in a column that has one of the following data types:
  • The CLOB data type holds text data.
  • The BLOB data type can store any kind of binary data in an undifferentiated byte stream.

The CLOB or BLOB column holds an LO handle for the smart large object. Therefore, when you select a CLOB or BLOB column, you do not obtain the actual data of the smart large object, but the LO handle that identifies this data. The BLOB and CLOB data types have identical internal representation. Externally, an LO handle is represented as a flat array of bytes with a length of MI_LO_SIZE.

Suppose an employee table has a BLOB column named emp_picture to hold the picture of an employee. The following figure shows that in a row of the employee table, the emp_picture column contains an LO handle. This LO handle contains information about the location of the actual employee picture in the sbspace1_100 sbspace.
Figure 1: A smart large object in a database column

begin figure description - This figure is described in the surrounding text. - end figure description

The CLOB and BLOB data types are often referred to collectively as smart-large-object data types.