SET compile_expressions = 1; SET min_count_to_compile_expression = 0; SELECT nan AS value, value = value, value = materialize(value), materialize(value) = value, materialize(value) = materialize(value); SELECT cast(nan, 'Float32') AS value, value = value, value = materialize(value), materialize(value) = value, materialize(value) = materialize(value); SELECT nan AS lhs, cast(nan, 'Float32') AS rhs, lhs = rhs, lhs = materialize(rhs), materialize(lhs) = rhs, materialize(lhs) = materialize(rhs); SELECT '--'; CREATE TABLE test_table ( id UInt32, value UInt32 ) ENGINE = MergeTree ORDER BY id; INSERT INTO test_table VALUES (76, 57); SELECT value FROM (SELECT stddevSamp(id) AS value FROM test_table) as subquery WHERE ((value = value) AND (NOT (value = value))); DROP TABLE test_table;