drop table if exists test.tab;
create table test.tab (date Date, x UInt64, s FixedString(128)) engine = MergeTree(date, (date, x), 8192);
insert into test.tab select today(), number, toFixedString('', 128) from system.numbers limit 8192;

set preferred_block_size_bytes = 2000000;
set preferred_max_column_in_block_size_bytes = 0;
select max(blockSize()), min(blockSize()), any(ignore(*)) from test.tab;
set preferred_max_column_in_block_size_bytes = 128;
select max(blockSize()), min(blockSize()), any(ignore(*)) from test.tab;
set preferred_max_column_in_block_size_bytes = 256;
select max(blockSize()), min(blockSize()), any(ignore(*)) from test.tab;
set preferred_max_column_in_block_size_bytes = 2097152;
select max(blockSize()), min(blockSize()), any(ignore(*)) from test.tab;
set preferred_max_column_in_block_size_bytes = 4194304;
select max(blockSize()), min(blockSize()), any(ignore(*)) from test.tab;

drop table if exists test.tab;
create table test.tab (date Date, x UInt64, s FixedString(128)) engine = MergeTree(date, (date, x), 32);
insert into test.tab select today(), number, toFixedString('', 128) from system.numbers limit 47;
set preferred_max_column_in_block_size_bytes = 1152;
select blockSize(), * from test.tab where x = 1 or x > 36 format Null;

drop table if exists test.tab;
create table test.tab (date Date, x UInt64, s FixedString(128)) engine = MergeTree(date, (date, x), 8192);
insert into test.tab select today(), number, toFixedString('', 128) from system.numbers limit 10;
set preferred_max_column_in_block_size_bytes = 128;
select s from test.tab where s == '' format Null;

drop table if exists test.tab;
create table test.tab (date Date, x UInt64, s String) engine = MergeTree(date, (date, x), 8192);
insert into test.tab select today(), number, 'abc' from system.numbers limit 81920;
set preferred_block_size_bytes = 0;
select count(*) from test.tab prewhere s != 'abc' format Null;
select count(*) from test.tab prewhere s = 'abc' format Null;