Version 0.2 of sAsync, "SQLAlchemy Done Asynchronously" has been released at http://foss.eepatents.com/sAsync. It provides a Twisted-compatible way to use SQLAlchemy.
There is a fair amount of documentation on the Trac site now, thanks in large part to users of the package.
sAsync offers asynchronous access to the outstanding SQLAlchemy package by Michael Bayer. It is built around an 'access broker' object that provides a priority-queued asynchronous interface to database accesses. This underlying transaction-queuing structure is much improved in version 0.2.
By wrapping your database-access methods in a @transact decorator, you can put the underlying method call in a queue with whatever scheduling priority you designate and immediately obtain a Deferred object that references the eventual result of the database transaction. The access broker also includes structure for convenient and integrated table setup, startup, and shutdown.
The package also provides higher-level SQLAlchemy enhancements including persistent item storage with deferred read and write results, and persistent dictionary, array, and graph objects using that storage. Text indexing and searching, again with deferred 'behind the scenes' processing, will be included at some point.
Best regards, Ed Suominen