date_histogram—dynamically produce many buckets. How does Elasticsearch decide the order that
these buckets are presented to the user?
By default, buckets are ordered by
doc_count in descending order. This is a
good default because often we want to find the documents that maximize some
criteria: price, population, frequency. But sometimes you’ll want to modify this sort order, and there are a few ways to
do it, depending on the bucket.