Not initially, but later I intend to allow the Silos to accept 'wrapped-up' transactions. I've previously worked with a DB-like system which allowed historic transactions to be reversed-out. This requires that the updates to the Silos become fine-grained - e.g. "update field 'foo' to the result of that query plus two", rather than just updating 'foo' to 42. This will take a lot of work, but will produce a system with very useful properties.

I want to focus on simply getting the core working first, without ACID guarantees.