function ret = ping(db)
% @TSDB/PING - Get status information about database connection
%
% >> ret = ping(db)
%
%
%   Copyright 2005-2007 Emmanuele Somma    (Servizio Studi Banca d'Italia)
%                       emmanuele.somma@bancaditalia.it - esomma@ieee.org
%
  ret = 1
%  ret = ping(db.conn);