A binary large object (BLOB) contains unstructured data and consists of a group of bytes. ABL has no special knowledge about its contents. Rather, ABL assumes that the data in a BLOB is managed by other software (such as a word processor, a spreadsheet program, or a bar-code reader). When working with BLOB values, offsets are always in bytes. With BLOB values, you can store data that is up to 1GB in size. For example, if you have an application with a catalogue of images you can now easily store those images in an OpenEdge database.

A BLOB field is a database table or temp-table field that contains a BLOB locator, which points to the associated BLOB data stored in the database. You cannot manipulate BLOB data directly. Instead, you must copy a BLOB to a MEMPTR, and then use the MEMPTR functionality to manipulate the binary contents of a BLOB field in ABL. (A MEMPTR contains a sequence of bytes in memory. You can think of the MEMPTR as a cache for the BLOB.) To copy data between a BLOB field and a MEMPTR, you can use either the COPY-LOB statement or you can use an assignment. See Copy large objects for more information.