Feature request : _approx_count_distinct


#1

https://docs.couchdb.org/en/2.2.0/ddocs/ddocs.html?highlight=_approx_count_distinct#_approx_count_distinct

Aproximates the number of distinct keys in a view index using a variant of the HyperLogLog algorithm. This algorithm enables an efficient, parallelizable computation of cardinality using fixed memory resources. CouchDB has configured the underlying data structure to have a relative error of ~2%.


Views and count distinct