http://i3xi5qxvbrngh3g6o7czwjfxwjzigook7zxzjmgwg5b7xnjcn5hzciad.onion/proposals/226-bridgedb-database-improvements.html
Choice of DDBS
CouchDB is chosen for its simple HTTP API, ease of use, speed, and official
support for Twisted Python applications. [4] Additionally, its
document-based data model is very similar to the current archetecture of
tor's Directory Server/Mirror system, in that an HTTP API is used to
retrieve data stored within virtual directories.