dbm is a simple
database package that comes with
X/Open-
compliant Unices. It allows the programmer to store
arbitrary blocks of
data in a regular file. Each block is
associated with a
key, which can later be used to
retrieve the data.
The drawbacks of dbm is that it's little more than an indexed file storage system; it is impossible to do complex queries or use SQL. On the plus side, it's lightweight, standard on most systems (FSF has produced a free version called gdbm), and has bindings for most popular languages.