drop table if exists data_02021; create table data_02021 (key Int) engine=MergeTree() order by key; insert into data_02021 values (1); -- { echoOn } select * from data_02021 prewhere 1 or ignore(key); select * from data_02021 prewhere 1 or ignore(key) where key = 1; select * from data_02021 prewhere 0 or ignore(key); select * from data_02021 prewhere 0 or ignore(key) where key = 1; -- { echoOff } drop table data_02021;