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; wherein the system further comprises: means for attempting to write, into the plurality of fields having a plurality of original values in a plurality of databases, a plurality of new values; and means for returning the plurality of fields to the plurality of original values to the plurality of original values if the attempt fails with respect to at least one of the plurality of fields.