from that page: A program accessing the database is free to decide how the data is to be stored in a record. Berkeley DB puts no constraints on the record's dat

from that page: A program accessing the database is free to decide how the data is to be stored in a record. Berkeley DB puts no constraints on the record's data. The record and its key can both be up to four gigabytes long. Berkeley DB supports database features such as ACID transactions, fine-grained locking, hot backups and replication.