# Chapter 26 The dbm library: access to NDBM databases

The `dbm` library provides access to NDBM databases under Unix. NDBM databases maintain key/data associations, where both the key and the data are arbitrary strings. They support fairly large databases (several gigabytes) and can retrieve a keyed item in one or two file system accesses. Refer to the Unix manual pages for more information.

> Unix: Programs that use the `dbm` library must be linked as follows:

>             ocamlc other options dbm.cma other files
>             ocamlopt other options dbm.cmxa other files

> For interactive use of the `dbm` library, do:

>             ocamlmktop -o mytop dbm.cma
>             ./mytop

or (if dynamic linking of C libraries is supported on your platform), start `ocaml` and type `#load "dbm.cma";;`.

> Windows: This library is not available.

- Module `Dbm`: interface to the NDBM database