title: which one to select (pg_basebackup or pg_dumpall )when migrating 9.3 to 9.4 postgres
body: <p>I am migrating my postgres 9.3 to 9.4 and for that i need to take backup of existing DB, so I am confused in 2 pg_basebackup and pg_dumpall.</p>
  
  <p>I am new to postgres, and help or suggestion will be very helpful.</p>