SET log_queries=1; SET log_profile_events=true; CREATE TABLE src Engine=MergeTree ORDER BY id AS SELECT number as id, toInt32(1) as value FROM numbers(1); CREATE TABLE dst (id UInt64, delta Int64) Engine=MergeTree ORDER BY id; -- First we try with default values (https://github.com/ClickHouse/ClickHouse/issues/9587) SET use_index_for_in_with_subqueries = 1; CREATE MATERIALIZED VIEW src2dst_true TO dst AS SELECT id, src.value - deltas_sum as delta FROM src LEFT JOIN ( SELECT id, sum(delta) as deltas_sum FROM dst WHERE id IN (SELECT id FROM src WHERE not sleepEachRow(0.001)) GROUP BY id ) _a USING (id); -- Inserting 2 numbers should require 2 calls to sleep INSERT into src SELECT number + 100 as id, 1 FROM numbers(2); -- Describe should not need to call sleep DESCRIBE ( SELECT '1947 #3 QUERY - TRUE', id, src.value - deltas_sum as delta FROM src LEFT JOIN ( SELECT id, sum(delta) as deltas_sum FROM dst WHERE id IN (SELECT id FROM src WHERE not sleepEachRow(0.001)) GROUP BY id ) _a USING (id) ) FORMAT Null; SYSTEM FLUSH LOGS; SELECT '1947 #1 CHECK - TRUE' as test, ProfileEvents['SleepFunctionCalls'] as sleep_calls, ProfileEvents['SleepFunctionMicroseconds'] as sleep_microseconds FROM system.query_log WHERE query like '%CREATE MATERIALIZED VIEW src2dst_true%' AND type > 1 AND current_database = currentDatabase() AND event_date >= yesterday() FORMAT JSONEachRow; SELECT '1947 #2 CHECK - TRUE' as test, ProfileEvents['SleepFunctionCalls'] as sleep_calls, ProfileEvents['SleepFunctionMicroseconds'] as sleep_microseconds FROM system.query_log WHERE query like '%INSERT into src SELECT number + 100 as id, 1 FROM numbers(2)%' AND type > 1 AND current_database = currentDatabase() AND event_date >= yesterday() FORMAT JSONEachRow; SELECT '1947 #3 CHECK - TRUE' as test, ProfileEvents['SleepFunctionCalls'] as sleep_calls, ProfileEvents['SleepFunctionMicroseconds'] as sleep_microseconds FROM system.query_log WHERE query like '%DESCRIBE ( SELECT ''1947 #3 QUERY - TRUE'',%' AND type > 1 AND current_database = currentDatabase() AND event_date >= yesterday() FORMAT JSONEachRow; DROP TABLE src2dst_true; -- Retry the same but using use_index_for_in_with_subqueries = 0 SET use_index_for_in_with_subqueries = 0; CREATE MATERIALIZED VIEW src2dst_false TO dst AS SELECT id, src.value - deltas_sum as delta FROM src LEFT JOIN ( SELECT id, sum(delta) as deltas_sum FROM dst WHERE id IN (SELECT id FROM src WHERE not sleepEachRow(0.001)) GROUP BY id ) _a USING (id); -- Inserting 2 numbers should require 2 calls to sleep INSERT into src SELECT number + 200 as id, 1 FROM numbers(2); -- Describe should not need to call sleep DESCRIBE ( SELECT '1947 #3 QUERY - FALSE', id, src.value - deltas_sum as delta FROM src LEFT JOIN ( SELECT id, sum(delta) as deltas_sum FROM dst WHERE id IN (SELECT id FROM src WHERE not sleepEachRow(0.001)) GROUP BY id ) _a USING (id) ) FORMAT Null; SYSTEM FLUSH LOGS; SELECT '1947 #1 CHECK - FALSE' as test, ProfileEvents['SleepFunctionCalls'] as sleep_calls, ProfileEvents['SleepFunctionMicroseconds'] as sleep_microseconds FROM system.query_log WHERE query like '%CREATE MATERIALIZED VIEW src2dst_false%' AND type > 1 AND current_database = currentDatabase() AND event_date >= yesterday() FORMAT JSONEachRow; SELECT '1947 #2 CHECK - FALSE' as test, ProfileEvents['SleepFunctionCalls'] as sleep_calls, ProfileEvents['SleepFunctionMicroseconds'] as sleep_microseconds FROM system.query_log WHERE query like '%INSERT into src SELECT number + 200 as id, 1 FROM numbers(2)%' AND type > 1 AND current_database = currentDatabase() AND event_date >= yesterday() FORMAT JSONEachRow; SELECT '1947 #3 CHECK - FALSE' as test, ProfileEvents['SleepFunctionCalls'] as sleep_calls, ProfileEvents['SleepFunctionMicroseconds'] as sleep_microseconds FROM system.query_log WHERE query like '%DESCRIBE ( SELECT ''1947 #3 QUERY - FALSE'',%' AND type > 1 AND current_database = currentDatabase() AND event_date >= yesterday() FORMAT JSONEachRow; DROP TABLE src2dst_false; DROP TABLE src; DROP TABLE dst;