elasticsearch/kibana — pull request #2106 by regit (2014-12-04 09:31:16+00:00)
Title: Use shard_size parameter in facets

Asking more work to ES by asking to use 10 times the size as
shard_size. This allows terms to be more accurate. As the size
specified in terms is often small, the impact on performance is
light.

With this modification, we got exact results on count and reverse
count if the number of different elements is not huge.