drop table if exists one_table; set allow_deprecated_syntax_for_merge_tree=1; create table one_table (date Date, one UInt64) engine = MergeTree(date, (date, one), 8192); insert into one_table select today(), toUInt64(1) from system.numbers limit 100000; SET preferred_block_size_bytes = 8192; select isNull(one) from one_table where isNull(one); drop table if exists one_table;