title: Best approach for BigQuery data transformations
body: <p>I already have terabytes of data stored on BigQuery and I'm wondering to perform heavy data transformations on it.</p>
  
  <p>Considering COSTS and PERFORMANCE, what the best approach you guys would suggest to perform these transformations for future usage of these data on BigQuery?</p>
  
  <p>I'm considering a few options:<br>
  1. Read raw data from DataFlow and then load the transformed data back into BigQuery?<br>
  2. Do it directly from BigQuery?</p>
  
  <p>Any ideas about how to proceed with this?</p>