-- Tags: no-s3-storage set allow_experimental_projection_optimization = 1, force_optimize_projection = 1; drop table if exists tp; create table tp (type Int32, device UUID, cnt UInt64) engine = MergeTree order by (type, device); insert into tp select number%3, generateUUIDv4(), 1 from numbers(300); alter table tp add projection uniq_city_proj ( select type, uniq(cityHash64(device)), sum(cnt) group by type ); alter table tp materialize projection uniq_city_proj settings mutations_sync = 1; drop table tp;