# File rbot/dbhash.rb, line 117
    def DBTree.open_db(name)
      debug "DBTree: opening existing db #{name}"
      return BDB::CIBtree.open name, nil, 
                             "r+", 0600, "set_pagesize" => 1024,
                             "set_cachesize" => [0, 32 * 1024, 0]
    end