ClickHouse/tests/integration/test_explain_estimates/test.py

import pytest

from helpers.cluster import ClickHouseCluster

cluster = ClickHouseCluster(__file__)
node1 = cluster.add_instance("instance")


@pytest.fixture(scope="module")
def start_cluster():
    try:
        cluster.start()
        yield cluster

    finally:
        cluster.shutdown()


def test_explain_estimates(start_cluster):
    node1.query(
        "CREATE TABLE test (i Int64) ENGINE = MergeTree() ORDER BY i SETTINGS index_granularity = 16"
    )
    node1.query("INSERT INTO test SELECT number FROM numbers(128)")
    node1.query("OPTIMIZE TABLE test")
    # sum(marks) - 1 because EXPLAIN ESIMATES does not include final mark.
    system_parts_result = node1.query(
        "SELECT any(database), any(table), count() as parts, sum(rows) as rows, sum(marks)-1 as marks FROM system.parts WHERE database = 'default' AND table = 'test' and active = 1 GROUP BY (database, table)"
    )
    explain_estimates_result = node1.query("EXPLAIN ESTIMATE SELECT * FROM test")
    assert system_parts_result == explain_estimates_result