In contrast with most other database systems, Berkeley DB provides relatively simple data access services. Records in Berkeley DB are (key, value) pairs. Berkeley DB supports only a few logical operations on records, as follows:
Inserting a record in a table.
Deleting a record from a table.
Finding a record in a table by looking up its key.
Updating a record that has already been found.
Notice that Berkeley DB never operates on the value part of a record. Values are simply payload to be stored with keys and reliably delivered back to the application on demand.
Both keys and values can be arbitrary bit strings, either fixed-length or variable-length. As a result, programmers can put native programming language data structures ...