title: MySQL query hangs on `SELECT COUNT(*)`
body: <p>I've been playing around with MySQL and sqlalchemy to gather and store data. Over the the weekend I was collecting tweets at about 20,000 tweets/hour and placing them in a table <code>raw_tweets</code> indexed by their tweet id. I am expecting ~1,000,000 rows, but when I run </p>
  
  <pre><code>SELECT COUNT(*) from raw_tweets;
  </code></pre>
  
  <p>the query just hangs. I've waited a few minutes and still nothing. My knowledge of sql is fairly limited. Is it possible there is a lock on the table? Would that cause it to hang without giving rise to an error? How can I go about diagnosing/fixing this problem?</p>
  
  <p>P.S. it looks like all my queries on that table are hanging.</p>