Patent ID: 8442971
Filing Date: 2013-05-14
Classification: G06F

Abstract:
1. A computer-implemented method comprising: designating a first driver source specified by a first execution plan that implements a query; designating a second driver source specified by a second execution plan that implements the query; executing a portion of the first execution plan; executing a portion of the second execution plan; if a unique identifier of a first row returned by the executing the portion of the first execution plan does not match all unique identifiers of all rows from the second driver source that were saved to a result set by the executing the portion of the second execution plan, adding the first row returned by the executing the portion of the first execution plan to the result set, and adding, to a unique identifier log, the unique identifier of the first row that was returned by the executing the portion of the first execution plan; and if the unique identifier of the first row returned by the executing the first execution plan matches a unique identifier of a row from the second driver source that was saved to the result set by the executing the second execution plan, refraining from adding the first row, to the result set, by the executing the first execution plan and refraining from adding the unique identifier of the first row, to the unique identifier log, that was returned by the executing the first execution plan.