No - it goes way beyond simple batches of operations. Basically you have to write your transaction as JavaScript program. So, you can do anything you could do o

No - it goes way beyond simple batches of operations. Basically you have to write your transaction as JavaScript program. So, you can do anything you could do on the client-side - with the exception of waiting for another source (i. e. user interaction). You could read a document from one collection, chose different actions based on the attribute. Change documents in multiple collections. I think the PHP driver uses some kind of abstraction to hide the JavaScript from the developer.