title: duplicates in bigquery table spread seconds of each other
body: <p>In my BigQuery table called [games] (around 5 million rows) where I have rows with the following structure:</p>
  
  <pre><code>user_id    game_id   game_play_time
  1234567    3444432   2017-05-30 15:26:57 UTC
  1234567    3444432   2017-05-30 15:26:58 UTC
  1234567    3444432   2017-05-30 15:26:59 UTC
  9876544    8586588   2017-05-30 23:26:11 UTC
  4638889    8698798   2017-05-30 15:26:58 UTC
  4638889    8698798   2017-05-30 15:27:58 UTC 
  </code></pre>
  
  <p>I need to remove rows which have the same user_id and game_id BUT where the time difference between following games 'is equal or less' than a second (keeping the first occurrence). </p>
  
  <p>The result should look as follow:</p>
  
  <pre><code>user_id    game_id   game_play_time
  1234567    3444432   2017-05-30 15:26:57 UTC
  9876544    8586588   2017-05-30 23:26:11 UTC
  4638889    8698798   2017-05-30 15:26:58 UTC
  4638889    8698798   2017-05-30 15:27:58 UTC 
  </code></pre>