I have a DB with a worrisome number of connections with pg_stat_activity.query = '/* DBD::Pg ping test v3.5.3 */', all of them with state='idle'. I have code that uses perl's ping method to ping the DB and I suspect this is the source. Is '/* DBD::Pg ping test v3.5.3 */' the last thing it did, but because it's idle now, it's actually doing nothing ?