As some of you might know, Google Analytics API doesn't always return precise data. Under certain circumstances, the data returned are sampled. Read more about sampling here.
You can choose from one of two anti-sampling algorithms - DailyWalk or Adaptive. Both are based on the same principle, to divide the wanted date range into smaller chunks.
DailyWalk as the name suggest divides the date range by days. So the extractor needs to make as many request as there are days in the date range.
Adaptive algorithm is using more sophisticated approach, and divides the date range into few smaller date ranges. Read in-depth explanation of the algorithm here, if you are interested.
DailyWalk algorithm might be more precise in some cases, but usually you will get the same results faster with the Adaptive algorithm.
Experiment with them and use what suits you best.