SET enable_optimize_predicate_expression = 0; select * from system.one l cross join system.one r; DROP TABLE IF EXISTS t1_00826; DROP TABLE IF EXISTS t2_00826; CREATE TABLE t1_00826 (a Int8, b Nullable(Int8)) ENGINE = Memory; CREATE TABLE t2_00826 (a Int8, b Nullable(Int8)) ENGINE = Memory; INSERT INTO t1_00826 values (1,1), (2,2); INSERT INTO t2_00826 values (1,1), (1,2); INSERT INTO t2_00826 (a) values (2), (3); SELECT 'cross'; SELECT * FROM t1_00826 cross join t2_00826 where t1_00826.a = t2_00826.a; SELECT 'cross nullable'; SELECT * FROM t1_00826 cross join t2_00826 where t1_00826.b = t2_00826.b; SELECT 'cross nullable vs not nullable'; SELECT * FROM t1_00826 cross join t2_00826 where t1_00826.a = t2_00826.b; SELECT 'cross self'; SELECT * FROM t1_00826 x cross join t1_00826 y where x.a = y.a and x.b = y.b; SELECT 'cross one table expr'; SELECT * FROM t1_00826 cross join t2_00826 where t1_00826.a = t1_00826.b order by (t1_00826.a, t2_00826.a, t2_00826.b); SELECT 'cross multiple ands'; SELECT * FROM t1_00826 cross join t2_00826 where t1_00826.a = t2_00826.a and t1_00826.b = t2_00826.b; SELECT 'cross and inside and'; SELECT * FROM t1_00826 cross join t2_00826 where t1_00826.a = t2_00826.a and (t1_00826.b = t2_00826.b and 1); SELECT 'cross split conjunction'; SELECT * FROM t1_00826 cross join t2_00826 where t1_00826.a = t2_00826.a and t1_00826.b = t2_00826.b and t1_00826.a >= 1 and t2_00826.b = 1; SELECT 'comma'; SELECT * FROM t1_00826, t2_00826 where t1_00826.a = t2_00826.a; SELECT 'comma nullable'; SELECT * FROM t1_00826, t2_00826 where t1_00826.b = t2_00826.b; SELECT 'cross'; EXPLAIN SYNTAX SELECT * FROM t1_00826 cross join t2_00826 where t1_00826.a = t2_00826.a; SELECT 'cross nullable'; EXPLAIN SYNTAX SELECT * FROM t1_00826, t2_00826 where t1_00826.a = t2_00826.a; SELECT 'cross nullable vs not nullable'; EXPLAIN SYNTAX SELECT * FROM t1_00826 cross join t2_00826 where t1_00826.a = t2_00826.b; SELECT 'cross self'; EXPLAIN SYNTAX SELECT * FROM t1_00826 x cross join t1_00826 y where x.a = y.a and x.b = y.b; SELECT 'cross one table expr'; EXPLAIN SYNTAX SELECT * FROM t1_00826 cross join t2_00826 where t1_00826.a = t1_00826.b; SELECT 'cross multiple ands'; EXPLAIN SYNTAX SELECT * FROM t1_00826 cross join t2_00826 where t1_00826.a = t2_00826.a and t1_00826.b = t2_00826.b; SELECT 'cross and inside and'; EXPLAIN SYNTAX SELECT * FROM t1_00826 cross join t2_00826 where t1_00826.a = t2_00826.a and (t1_00826.a = t2_00826.a and (t1_00826.a = t2_00826.a and t1_00826.b = t2_00826.b)); SELECT 'cross split conjunction'; EXPLAIN SYNTAX SELECT * FROM t1_00826 cross join t2_00826 where t1_00826.a = t2_00826.a and t1_00826.b = t2_00826.b and t1_00826.a >= 1 and t2_00826.b > 0; DROP TABLE t1_00826; DROP TABLE t2_00826;