Patent ID: 8346714

Claim:
A method comprising: accepting a load-job for an active data warehouse (“ADW”) on a massively parallel processing system (“MPP system”), the MPP system comprising a plurality of units of parallelism, each of the plurality of units of parallelism maintaining its own moving system time separate from that of the other units of parallelism, the load-job including (a) a requested modification to a first identified row in a first temporal table, the first temporal table comprising rows stored in each of the plurality of units of parallelism, the first identified row being stored in the first temporal table on a first of the MPP system's units of parallelism, and (b) a requested modification to a second identified row in a second temporal table, the second temporal table comprising rows stored in a plurality of the plurality of units of parallelism, the second identified row being stored in the second temporal table on a second of the MPP system's units of parallelism; implementing the requested modifications on the first identified row and the second identified row; timestamping the first identified row with the moving system time maintained by the first of the MPP system's units of parallelism at the time of the implementation of the modification to the first identified row; and timestamping the second identified row with the moving system time maintained by the second of the MPP system's units of parallelism at the time of the implementation of the modification to the second identified row; wherein accepting the requested modification comprises: accepting multiple modifications to the first identified row within a time less than a finest granularity provided by the system time maintained by the first of the MPP system's units of parallelism; and generating an artificial finer granularity for the system time maintained by the first of the MPP system's units of parallelism to use as respective time stamps for successive modifications of the multiple modifications to the first identified row within a time less than the finest granularity available from the system time maintained by the first of the MPP system's units of parallelism.