Binary Large Object

Binary Large Objects (BLOBs ) are large binary objects such as images or audio files. The term is often used in conjunction with databases and open source projects.


For a database BLOBs are not structured objects or field data. Some databases allow the field types can store volumes of data (quasi complete file ) as the field content.

Character Large Object ( CLOB or text ) are similar to BLOBs, but contain strings.

For international projects, storing Unicode data is often required. Many database vendors offer special LOB data types where multiple bytes can be used for the storage of the individual characters.

Another method for the storage of large objects is referred to as Open Prepress Interface (OPI).

If the column of a table in a relational database system disclosed as BLOB, most database management systems store the actual LOB value separately and record within the table only one key or a reference to this LOB value.

BLOBs are displayed in the current database systems due to different data types:

In the Java language, an interface named Blob in the JDBC connecting Java with database systems exists. Thus one can determine the length of a BLOB and also make access to the value itself.

Free Software and Open Source Projects

In the context of open source is desirable that all parts of the program can be generated from a publicly available source code. Occasionally, however, are also proprietary components, particularly device drivers, involved in such projects, which are exclusively provided in binary form and licensed and whose source code will not be published. Such components are called " blobs " means. The inclusion of such a " blob " in open source projects is controversial. In some Free Software projects ( such as Debian ) are not included under the definition of " free software" of the FSF, such proprietary programs or drivers and removed upon discovery.