title: Sqlalchemy Snowflake not closing connection after successfully retrieving results
body: <p>I am connecting to <a href="https://www.snowflake.net/product/" rel="nofollow noreferrer">snowflake datawarehouse</a> from Python and I encounter a weird behavior. The Python program exits successfully if I retrieve fewer number of rows from SnowFlake but hangs in there in-definitely if I try to retrieve more than 200K rows. I am 100% sure that there are no issues with my machine because I am able to retrieve 5 to 10 million rows from other type of database systems such as Postgres.</p>
  
  <p>My Python environment is Python 3.6 and I use the following version of the libraries -> SQLAlchemy 1.1.13, snowflake-connector-python 1.4.13, snowflake-sqlalchemy 1.0.7,</p>
  
  <p>The following code prints the total number of rows and closes the connection.</p>
  
  <pre><code>from sqlalchemy import create_engine
  from snowflake.sqlalchemy import URL
  
  engine = create_engine(URL(
              account=xxxx,
              user=xxxxx,
              password=xxxxx,
              database=xxxxx,
              schema=xxxxxx,
              warehouse=xxxxx))
  
  query = """SELECT * FROM db_name.schema_name.table_name LIMIT 1000"""
  
  results = engine.execute(query)
  print (results.rowcount)
  engine.dispose()
  </code></pre>
  
  <p>The following code prints the total number of rows but the connection doesn't close, it just hangs in there until I manually kill the Python process. </p>
  
  <pre><code>from sqlalchemy import create_engine
  from snowflake.sqlalchemy import URL
  
  engine = create_engine(URL(
              account=xxxx,
              user=xxxxx,
              password=xxxxx,
              database=xxxxx,
              schema=xxxxxx,
              warehouse=xxxxx))
  
  query = """SELECT * FROM db_name.schema_name.table_name LIMIT 500000"""
  
  results = engine.execute(query)
  print (results.rowcount)
  engine.dispose()
  </code></pre>
  
  <p>I tried multiple different tables and I encounter the same issue with SnowFlake. Did anyone encounter similar issues?</p>