Count distinct on elastic search

Question

How to achieve count distinct function on elastic search type using sql4es driver?

Select distinct inv_number , count(1) from invoices;

But it returns the total count of the particular invoice number.

Answer 1

Elasticsearch doesn't support deterministic DISTINCT counts (source). It supports only approximate distinct counters like "cardinality". One way to count distincts in a deterministic way is to aggregate them using "terms" and count buckets from result.