drop table if exists table_01323_many_parts; set remote_filesystem_read_method = 'read'; set local_filesystem_read_method = 'pread'; set load_marks_asynchronously = 0; set allow_asynchronous_read_from_io_pool_for_merge_tree = 0; create table table_01323_many_parts (x UInt64) engine = MergeTree order by x partition by x % 100; set max_partitions_per_insert_block = 100; insert into table_01323_many_parts select number from numbers(100000); set max_threads = 16; set log_queries = 1; select x from table_01323_many_parts limit 10 format Null; system flush logs; select peak_threads_usage <= 4 from system.query_log where current_database = currentDatabase() AND event_date >= today() - 1 and query ilike '%select x from table_01323_many_parts%' and query not like '%system.query_log%' and type = 'QueryFinish' order by query_start_time desc limit 1; select x from table_01323_many_parts order by x limit 10 format Null; system flush logs; select peak_threads_usage <= 36 from system.query_log where current_database = currentDatabase() AND event_date >= today() - 1 and query ilike '%select x from table_01323_many_parts order by x%' and query not like '%system.query_log%' and type = 'QueryFinish' order by query_start_time desc limit 1; drop table if exists table_01323_many_parts;