TinyCDB is a very fast and simple package for creating and reading constant
data bases, a data structure introduced by Dan J. Bernstein in his cdb package.
It may be used to speed up searches in a sequence of (key,value) pairs with
very big number of records. Example usage is indexing a big list of users -
where a search will require linear reading of a large /etc/passwd file, and for
many other tasks. It's usage/API is similar to ones found in BerkeleyDB, gdbm
and traditional *nix dbm/ndbm libraries, and is compatible in great extent to
cdb-0.75 package by Dan Bernstein.

CDB is a constant database, that is, it cannot be updated at a runtime, only
rebuilt. Rebuilding is atomic operation and is very fast - much faster than of
many other similar packages. Once created, CDB may be queried, and a query
takes very little time to complete.