title: Reflection in SQLAlchemy doesn't work for MS SQL Server system tables?
body: <p>I'm trying to reflect system table in MS SQL Server database:</p>
  
  <pre><code>from sqlalchemy import engine, create_engine, MetaData, Table 
  
  meta = MetaData() 
  
  url = engine.url.URL(
      "mssql+pyodbc",
      username=credentials["username"],
      password=credentials["pswd"],
      host=credentials["host"],
      database=credentials["db"],
      query=dict(driver="ODBC Driver 13 for SQL Server")
  )
  
  e = create_engine(url)
  conn = e.connect()
  tt = Table("objects", meta, autoload=True, autoload_with=e, schema="sys")
  for c in tt.columns:
      print(c.name)
  </code></pre>
  
  <p>At the end I get NoSuchTable error. I tried to reflect other system tables (sys.triggers, sys.sql_modules) - same results. With ordinary tables this code works normally, I can list columns and make other queries. Login which I use in my application has "db_owner" role, so it has enough permissions, and if I write something like this </p>
  
  <pre><code>for item in conn.execute("select * from sys.triggers"):
      print(item)
  </code></pre>
  
  <p>it works fine. </p>
  
  <p>What am I doing wrong? Is there any other way to work with data from system tables, besides executing raw sql and wrapping results in dataclasses etc.?</p>