1. A computer program product, comprising: a computer readable storage device having computer readable program code embodied therewith, where the computer readable program code when executed on a computer causes the computer to: provide, via a transaction coordinator, an indication to a transaction participant as part of a message originating from the transaction coordinator, where the message indicates that the transaction coordinator, that coordinates commitment of transactions as requested by an application, supports a heuristic response from the transaction participant that is sent to the transaction coordinator during coordination of the transactions as requested by the application in response to a determination by the transaction participant of a heuristic outcome, where heuristic outcomes comprise situations where transaction participants determine they are unable to honor transactional prior prepared commitments made to the transaction coordinator during first prepare phases of two-phase commits associated with the transactions, and the transactional prior prepared commitments comprise indications to the transaction coordinator that the transaction participants are prepared during the first prepare phases of the two-phase commits to commit respective portions of the transactions when instructed by the transaction coordinator, and where the message is ignorable by transaction participants that are incapable of communicating the heuristic response to the transaction coordinator and where the heuristic response from the transaction participant sent to the transaction coordinator indicates that the transaction participant determined that it is unable to honor a transactional prior prepared commitment made to the transaction coordinator by the transaction participant during a first prepare phase of a two-phase commit associated with a transaction coordinated by the transaction coordinator as requested by the application.