title: Data count in Athena is not right
body: <p>I have a table as described in <a href="https://i.stack.imgur.com/PeBPX.png" rel="nofollow noreferrer">the attached image</a>.
  Its data is coming from Firehose (maximum buffers: 128 MB or 900 seconds)</p>
  
  <ul>
  <li><p>When I try a simple count, it returns an awkward number, 296!
  though the size of scanned data is huge, 12GB, compared to 5KB for each record in this dataset</p></li>
  <li><p>When I try to load &amp; process that dataset in Glue Job, it'd return the expected count: 1778072</p></li>
  </ul>
  
  <p>I wonder if the cause was of the field <code>request_query</code> with type <code>array&lt;string&gt;</code></p>
  
  <p>Since the job is used for actual workflow, there're times I want to query just basic data like <code>ip</code>, <code>http_user_agent</code>, ...
  and this schema is enough for those tasks, without a need for writing another job script and waiting for its succeeded</p>
  
  <p>Hope that there're some ways to work it out</p>
  
  <p>* EDIT</p>
  
  <p>I'm running from Athena console. Here few sample queries:</p>
  
  <pre class="lang-sql prettyprint-override"><code>SELECT count(case when request_api = 'collections' then 1 end)
  FROM "request_events"
  where event_day = '2020-03-01'
  and tenant_id = 'devsite.com'
  
  SELECT request_api, count(*)
  FROM "request_events"
  where event_day = '2020-03-01'
  and tenant_id = 'devsite.com'
  group by request_api
  </code></pre>
  
  <ul>
  <li>EDIT 2</li>
  </ul>
  
  <p>Attached file for a <a href="https://drive.google.com/open?id=1ABnFSc9gpeNzXuDS6q1w_IbxfuRbHVdu" rel="nofollow noreferrer">sample data</a> of 12 records I have tested and the result was 1 record </p>