They implement a space efficent write-once database with fast access
path. Switch the services(5) database to use cdb. The size of the
database file decreases from 2.1MB disk space to 307KB. Access
performance is about the same if setservent(0) is used and about an
order of magnitude faster otherwise. services_mkdb defaults to the new
format, but can optionally create the old db(3) format as well for
statically linked legacy applications.