message: Addded documentation for Teradata DB
  Documentation extension for PR5870
diff: @@ -354,6 +354,8 @@ Here's a list of some of the recommended packages.
  +---------------+-------------------------------------+-------------------------------------------------+
  | BigQuery | ``pip install pybigquery`` | ``bigquery://`` |
  +---------------+-------------------------------------+-------------------------------------------------+
  +| Teradata | ``pip install sqlalchemy-teradata`` | ``teradata://`` |
  ++---------------+-------------------------------------+-------------------------------------------------+
  Note that many other database are supported, the main criteria being the
  existence of a functional SqlAlchemy dialect and Python driver. Googling
  @@ -399,6 +401,22 @@ use version 1.1.0 or try a newer version.
  See `Snowflake SQLAlchemy <https://github.com/snowflakedb/snowflake-sqlalchemy>`_.
  +Teradata
  +---------
  +
  +The connection string for Teradata looks like this ::
  +
  + teradata://{user}:{password}@{host}
  +
  +*Note*: Its required to have Teradata ODBC drivers installed and environment variables configured for proper work of sqlalchemy dialect. Teradata ODBC Drivers available here: https://downloads.teradata.com/download/connectivity/odbc-driver/linux
  +
  +Required environment variables: ::
  +
  + export ODBCINI=/.../teradata/client/ODBC_64/odbc.ini
  + export ODBCINST=/.../teradata/client/ODBC_64/odbcinst.ini
  +
  +See `Teradata SQLAlchemy <https://github.com/Teradata/sqlalchemy-teradata>`_.
  +
  Caching
  -------
  