1. A tangible machine readable medium including code, which when executed, causes the machine to perform the operations of: maintaining a most recent transaction timestamp to be updated upon commit of each of a plurality of transactions; starting a new transaction; in response to encountering a current read in the new transaction, determining if the most recent transaction timestamp has been updated from starting the new transaction to the current read; determining if a current read set for the new transaction including reads encountered from starting the new transaction to the current read are valid in response to determining the most recent transaction timestamp has been updated since starting the new transaction; and continuing execution of the new transaction in response to determining the most recent transaction timestamp has not been updated since starting the new transaction or determining the current read set is valid; and aborting the new transaction in response to determining the current read set is not valid.