question: void update ( long timeNanos , int rows ) { count ++ ; executionTimeMinNanos = Math . min ( timeNanos , executionTimeMinNanos ) ; executionTimeMaxNanos = Math . max ( timeNanos , executionTimeMaxNanos ) ; rowCountMin = Math . min ( rows , rowCountMin ) ; rowCountMax = Math . max ( rows , rowCountMax ) ; double rowDelta = rows - rowCountMean ; rowCountMean += rowDelta / count ; rowCountM2 += rowDelta * ( rows - rowCountMean ) ; double timeDelta = timeNanos - executionTimeMeanNanos ; executionTimeMeanNanos += timeDelta / count ; executionTimeM2Nanos += timeDelta * ( timeNanos - executionTimeMeanNanos ) ; executionTimeCumulativeNanos += timeNanos ; rowCountCumulative += rows ; lastUpdateTime = System . currentTimeMillis ( ) ; }
target:  Update the statistics entry.