title: Can the pub / sub message ID be held as a number?
body: <p>Pub/sub guarantes that messageId is always unique number. Therefore, i use this id as deviceId and i hold this value on bigquery table. Google documents say this value string. But, messageId return 15-digit number according to my experiments. Should I keep this value as number on bigquery? Does it cause any trouble?</p>
  
  <p><a href="https://cloud.google.com/pubsub/docs/reference/rest/v1/PubsubMessage" rel="nofollow noreferrer">Pubsub Message Format</a></p>