Transactions in Rails

Transactions in Rails are starting to bother me, and quite a lot. Once in a while I dive into my latest application,booki.es, a web application for trading long-term futures using play money.

Rails was fantastic for building my wife's eCommerce site: fairly static content and not many associations between entities. Rails transactional block was sufficient, something of the sorts of:

Account.transaction do
account1.deposit(100)
account2.withdraw(100)
end

Account.transaction(peter, paul) do
paul.deposit(350)
peter.withdraw(350)
end

Even ActiveRecord takes care of the transaction integrity for parent-child relationships, so when you save the parent, all child rows get also saved.

Now when a trade is exectued in my trading application, an update and a few reads happen on quite a few tables, including trades, positions, accounts, and historics, but some of these entities don't have any relationships between them. I need to ensure data integrity and atomicity, and Rails does not seem to have anything like the Java Transaction API (JTA).

I would love a simple transaction API like JTA being exposed for databases, like there is Transaction::Simple, but for databases. Ideally, I would like to have nested transactional support, even if it is a flatten model like in JTS.

But I don't have it, so I am having to modify my controllers and models to overcome the limitation. And to be honest this sucks. Maybe I should go back to my Tapestry/Spring/Hibernate combo for this one app. The right tool for the right job ...