drop table if exists tab_00577; create table tab_00577 (date Date, version UInt64, val UInt64) engine = ReplacingMergeTree(version) partition by date order by date settings enable_vertical_merge_algorithm = 1, vertical_merge_algorithm_min_rows_to_activate = 1, vertical_merge_algorithm_min_columns_to_activate = 0; insert into tab_00577 values ('2018-01-01', 2, 2), ('2018-01-01', 1, 1); insert into tab_00577 values ('2018-01-01', 0, 0); select * from tab_00577 order by version; OPTIMIZE TABLE tab_00577; select * from tab_00577; drop table tab_00577;