When using the _search API of Elasticsearch, if you set size to 10, and perform an avg metric aggregation, the average will be of all values across the dataset matching the query, not just the average of the 10 items returned in the hits array.
On the other hand, if you perform a terms aggregation and set the size of the terms aggregation to be 10, then performing an avg_buckets aggregation on those terms buckets will calculate an average over only those 10 buckets - not all potential buckets.
How can I calculate the an average of some field across all potential buckets, but still only have 10 items in the buckets array?