ClickHouse/dbms/tests/integration/test_non_default_compression/configs/zstd_compression_by_default.xml

<yandex>
    <compression>
        <case>
            <!-- Conditions. All must be satisfied simultaneously. Some conditions may not be specified. -->
            <min_part_size>0</min_part_size>         <!-- The minimum size of a part in bytes. -->
            <min_part_size_ratio>0</min_part_size_ratio>    <!-- The minimum size of the part relative to all the data in the table. -->
            <!-- Which compression method to choose. -->
            <method>zstd</method>
            <level>2</level>
        </case>
    </compression>
</yandex>