1. A system comprising: a database system comprising: a first database tangibly stored in at least a first computer-readable medium; first atomic transaction means for using a first processor communicatively coupled to a first memory to execute a first component transaction instance atomically on the first database, the first atomic transaction means comprising: first operation execution means to perform a first operation to produce first application data within an atomicity guarantee of the first component transaction instance; first application data storage means for storing the first application data in a first record of the first database within the atomicity guarantee of the first component transaction instance; first state storage means for storing a first state of a computation, based on the first operation, in a second record of the first database within the atomicity guarantee of the first component transaction instance; a second database tangibly stored in at least a second computer-readable medium; second atomic transaction means for using a second processor communicatively coupled to a second memory to execute a second component transaction instance atomically on the second database, the second atomic transaction means comprising: means for reading the first state of the computation from the second record of the first database; second operation execution means to perform a second operation, in response to the first state, to produce second application data within an atomicity guarantee of the second component transaction instance; second application data storage means for storing the second application data in a third record of the second database within the atomicity guarantee of the second component transaction instance; and second state storage means for storing a second state of the computation, based on the second operation, in a fourth record of the second database within the atomicity guarantee of the second component transaction instance.