ClickHouse/tests/performance/asof.xml

<test>

    <preconditions>
        <table_exists>test.hits</table_exists>
    </preconditions>

    <query>
        SELECT *
        FROM
        (
            SELECT
                RegionID,
                toDateTime(EventDate) AS date,
                count() AS quantity
            FROM test.hits
            GROUP BY
                RegionID,
                date
        ) AS regions
        ASOF LEFT JOIN
        (
            SELECT
                RegionID,
                EventTime
            FROM test.hits
        ) AS ids ON (regions.RegionID = ids.RegionID) AND (regions.date &lt; ids.EventTime)
    </query>

</test>