ClickHouse/tests/performance/fuse_sumcount.xml

<test>
    <!-- We test rewriting sum(), avg(), count() to a single call of sumCount() here.
         As a reference, we use the same queries with the optimization disabled.
         sum() has a highly optimized algorithm, so alone it will be faster than sumCount(),
         but when we add count() or avg(), the sumCount() should win.
         Also test GROUP BY with and without keys, because they might have different
         optimizations. -->
    <settings>
        <optimize_syntax_fuse_functions>1</optimize_syntax_fuse_functions>
    </settings>

    <substitutions>
        <substitution>
            <name>key</name>
            <values>
                <value>1</value>
                <value>intHash32(number) % 1000</value>
            </values>
        </substitution>
    </substitutions>

    <query>SELECT sum(number)                             FROM numbers(1000000000) FORMAT Null</query>
    <query>SELECT sum(number), count(number)              FROM numbers(1000000000) FORMAT Null</query>
    <query>SELECT sum(number), count(number)              FROM numbers(1000000000) SETTINGS optimize_syntax_fuse_functions = 0 FORMAT Null</query>
    <query>SELECT sum(number), avg(number), count(number) FROM numbers(1000000000) FORMAT Null</query>
    <query>SELECT sum(number), avg(number), count(number) FROM numbers(1000000000) SETTINGS optimize_syntax_fuse_functions = 0 FORMAT Null</query>

    <query>SELECT sum(number)                             FROM numbers(100000000) GROUP BY intHash32(number) % 1000 FORMAT Null</query>
    <query>SELECT sum(number), count(number)              FROM numbers(100000000) GROUP BY intHash32(number) % 1000 FORMAT Null</query>
    <query>SELECT sum(number), count(number)              FROM numbers(100000000) GROUP BY intHash32(number) % 1000 SETTINGS optimize_syntax_fuse_functions = 0 FORMAT Null</query>
    <query>SELECT sum(number), avg(number), count(number) FROM numbers(100000000) GROUP BY intHash32(number) % 1000 FORMAT Null</query>
    <query>SELECT sum(number), avg(number), count(number) FROM numbers(100000000) GROUP BY intHash32(number) % 1000 SETTINGS optimize_syntax_fuse_functions = 0 FORMAT Null</query>
</test>