How to get multiple result sets from single query?

ClickHouse sometimes returns multiple tables from single query. For instance, you may specify GROUP BY WITH ROLLUP and get multiple tables. So how is it possible to retrieve such results w/ JDBC or new clickhouse-client interface? Looking into the JDBC code, it seems the statement implementation doesn’t support getMoreResults() in such a way.

[zhicwu]

Yes, it will append a few more aggregated rows to the same result set. It’s probably better to return multiple result sets instead.

SELECT year, month, day, count(*)
FROM (
	select 2019 as year, 1 as month, 5 as day
	union all
	select 2019 as year, 1 as month, 15 as day
	union all
	select 2020 as year, 10 as month, 5 as day
) t 
GROUP BY year, month, day WITH ROLLUP

[den-crane]

There is zero guarantee that WITH ROLLUP returns in multiple blocks in Native format. Basically it just the current behavior, it can be changed tomorrow.