I have an unexpected performance difference between the SamplingAccumulator and the StandardFacetAccumulator.
The case is an index with about 5M documents and each document containing about 10 fields. I created a facet on each of those fields. When searching to retrieve facet-counts (using 1 CountFacetRequest), the SamplingAccumulator is about twice as fast as the StandardFacetAccumulator. This is expected and a nice speed-up.
However, when I use more CountFacetRequests to retrieve facet-counts for more than one field, the speeds of the SampingAccumulator decreases, to the point where the StandardFacetAccumulator is faster.
Is this behaviour normal? I did not expect it, as the SamplingAccumulator needs to do less work?
Some code to show what I do: