ClickHouse/tests/performance/vector_binary_serialization.xml

<test>
    <!--
        Exercises binary (de)serialization of std::vector of trivially-serializable
        elements via writeVectorBinary / readVectorBinary.

        The analysisOfVariance aggregate state holds three contiguous vectors
        (std::vector<Float64> twice and std::vector<UInt64>), one element per group.
        With many groups these vectors are large, so the bulk single-copy path added
        in this change replaces an element-by-element (de)serialization loop.

        Writing the AggregateFunction column to MergeTree serializes the state
        (writeVectorBinary); reading it back deserializes it (readVectorBinary).
    -->
    <create_query>
        CREATE TABLE aov_states
        (
            key UInt32,
            state AggregateFunction(analysisOfVariance, Float64, UInt32)
        )
        ENGINE = MergeTree ORDER BY key
    </create_query>

    <!-- 200 states, each holding ~100000 groups => ~480 MB of vector data total.
         The fill itself serializes the states when writing the parts. -->
    <fill_query>
        INSERT INTO aov_states
        SELECT
            intDiv(number, 100000) % 200 AS key,
            analysisOfVarianceState(number * 1.5, (number % 100000)::UInt32)
        FROM numbers_mt(20000000)
        GROUP BY key
    </fill_query>

    <!-- Deserialization only (readVectorBinary). -->
    <query>SELECT state FROM aov_states FORMAT Null</query>

    <!-- Deserialization followed by merging the states. -->
    <query>SELECT analysisOfVarianceMergeState(state) FROM aov_states GROUP BY key FORMAT Null</query>

    <drop_query>DROP TABLE IF EXISTS aov_states</drop_query>
</test>