Sub-aggregations on both engines: bleve folds child buckets below their parent through the same collector, OpenSearch nests them natively, so a request stays one search per space. The proto gains sub_aggregations on the option and on the bucket; merge, finalize, validation and the bucket limit walk every level, results are positional at every level, a metric has no buckets to nest in. AGG-10 to AGG-15, 20, 35, 40 and 44 in the parity suite, AGG-14 as a known OpenSearch divergence.
Dominik Schmidt
f5cdd20b2c