title: Sqlalchemy setup for postgresql with timescaledb extension
body: <p>I was trying to hook up the sqlalchemy with my underlying postgresql, which uses the timescaledb extension. All queries work fine when I try them from the psql terminal client. But when I try to use python &amp; sqlalchemy to do it, it keeps throwing me an error.</p>
  
  <p>Here's the very basic code snippet that I try to test it with:</p>
  
  <pre><code>engine = create_engine('postgres://usr:pwd@localhost:5432/postgres', echo=True)
  engine.execute('select 1;')
  </code></pre>
  
  <p>And it always shows the following the error message:</p>
  
  <pre><code>File "/home/usr/.local/share/virtualenvs/redbird-lRSbFM0t/lib/python3.6/site-packages/psycopg2/extras.py", line 917, in get_oids
  """ % typarray)
  sqlalchemy.exc.OperationalError: (psycopg2.OperationalError) could not access file "timescaledb-0.9.0": No such file or directory
  </code></pre>
  
  <p>The connection to the db is fine, otherwise it won't know the db is using timescaledb.</p>
  
  <p>Any one has any insights?</p>
  
  <p><strong>UPDATE:</strong> I try to use psycopg2 directly. It basically gives the same error. DB is connected successfully, but timescaledb-0.9.0 cannot be accessed.</p>
  
  <p>Here's the code snippted</p>
  
  <pre><code>conn_string = "host='localhost' dbname='db' user='usr' password='pwd'"
  print("Connecting to database\n -&gt;%s " % (conn_string))
  
  conn = psycopg2.connect(conn_string)
  cursor = conn.cursor()
  print("Connected!\n")
  
  cursor.execute("\dx")
  records = cursor.fetchall()
  </code></pre>
  
  <p>Here's the exact same error message:</p>
  
  <pre><code>Connecting to database
  Connected!
  
  Traceback (most recent call last):
  File "/home/usr/Workspace/somepath/web/model/model.py", line 21, in &lt;module&gt;
  cursor.execute("\dx")
  psycopg2.OperationalError: could not access file "timescaledb-0.9.0": No such file or directory
  </code></pre>