ClickHouse/tests/performance/insert_sequential_and_background_merges.xml

<?xml version="1.0" encoding="utf-8"?>
<test>
    <settings>
        <max_threads>1</max_threads>
        <max_block_size>1</max_block_size>
        <min_insert_block_size_rows>1</min_insert_block_size_rows>
    </settings>
    <create_query>CREATE TABLE t (x UInt64) ENGINE = MergeTree() ORDER BY tuple()</create_query>
    <query>INSERT INTO t SELECT * FROM numbers(3000)</query>
    <drop_query>DROP TABLE IF EXISTS t</drop_query>
</test>