title: BigTable design for nested (array) data
body: <p>We are loading data in batch from BigQuery to BigTable. API's access the data via Cloud Functions in BigTable. The header data and the details are fetched in two different calls in the current architecture. However I wanted to store both header and details in one column family. So far, I didn't find any references or examples explaining how to store arrays in BigTable, so I guess it's not possible. Now what would be the best alternative design to be able to serve the API layer, for my case.
  A simplified example of the data, where call_replies is a STRUCT in BigQuery:</p>
  <pre><code>[
     {
        &quot;call_id&quot;:&quot;123&quot;,
        &quot;caller&quot;:&quot;Jeff&quot;,
        &quot;call_creation_timestamp&quot;:&quot;2020-01-01 19:20:35&quot;,
        &quot;call_replies&quot;:[
           {
              &quot;email&quot;:&quot;Bladiebla@gmail.com&quot;,
              &quot;message&quot;:&quot;Bladiebla&quot;
           },
           {
              &quot;email&quot;:&quot;jaryjary@gmail.com&quot;,
              &quot;message&quot;:&quot;Jaryjary&quot;
           }
        ]
     },
     {
        &quot;call_id&quot;:&quot;456&quot;,
        &quot;caller&quot;:&quot;John&quot;,
        &quot;call_creation_timestamp&quot;:&quot;2020-01-01 20:20:35&quot;,
        &quot;call_replies&quot;:[
           
        ]
     }
  ]
  </code></pre>
  <p>Thanks in advance experts for your help!</p>