Close and re-connect SQLAlchemy session's database connection?

Question

Suppose we need to do some long-time computing after loading some objects from SQLAlchemy session, we want to close the database connection during the computing, then reconnect to the database. How to do it in SQLAlchemy?

Or, is it necessary to close the session and re-create one every time, and merge/reload all related objects? But I found session.close() doesn't close the connection, even session.connection().close() or close the connection bound to the session doesn't close it either. So how to close the connection, after I used a session and before I quit the application?

Answer 1

Got the answer from the SQLAlchemy Google Group: use session.bind.dispose() after terminating the on-going transaction. It disposes the whole connection pool, so all database connections are closed.

And I can hold the session, e.g. commit or rollback the session instead of closing it. When I need to use it later, it'll automatically make necessary connections. This method saves me from recreating the session and merging objects.