ClickHouse/tests/integration/test_merge_table_over_distributed/test.py

from contextlib import contextmanager

import pytest
from helpers.cluster import ClickHouseCluster

cluster = ClickHouseCluster(__file__)

node1 = cluster.add_instance("node1", main_configs=["configs/remote_servers.xml"])
node2 = cluster.add_instance("node2", main_configs=["configs/remote_servers.xml"])


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

        for node in (node1, node2):
            node.query(
                """
CREATE TABLE local_table(id UInt32, val String) ENGINE = MergeTree ORDER BY id;
CREATE TABLE local_table_2(id UInt32, val String) ENGINE = MergeTree ORDER BY id;
"""
            )

        node1.query("INSERT INTO local_table VALUES (1, 'node1')")
        node2.query("INSERT INTO local_table VALUES (2, 'node2')")

        node1.query(
            """
CREATE TABLE distributed_table(id UInt32, val String) ENGINE = Distributed(test_cluster, default, local_table);
CREATE TABLE distributed_table_2(id UInt32, val String) ENGINE = Distributed(test_cluster, default, local_table_2);
CREATE TABLE merge_table(id UInt32, val String) ENGINE = Merge(default, '^distributed_table')
"""
        )

        yield cluster

    finally:
        cluster.shutdown()


def test_global_in(started_cluster):
    assert (
        node1.query(
            "SELECT val FROM distributed_table WHERE id GLOBAL IN (SELECT toUInt32(3 - id) FROM local_table)"
        ).rstrip()
        == "node2"
    )

    assert (
        node1.query(
            "SELECT val FROM merge_table WHERE id GLOBAL IN (SELECT toUInt32(3 - id) FROM local_table)"
        ).rstrip()
        == "node2"
    )


def test_filtering(started_cluster):
    assert (
        node1.query("SELECT id, val FROM merge_table WHERE id = 1").rstrip()
        == "1\tnode1"
    )

    assert (
        node1.query("SELECT id + 1, val FROM merge_table WHERE id = 1").rstrip()
        == "2\tnode1"
    )

    assert (
        node1.query("SELECT id + 1 FROM merge_table WHERE val = 'node1'").rstrip()
        == "2"
    )

    assert (
        node1.query(
            "SELECT id + 1, val FROM merge_table PREWHERE id = 1 WHERE _table != '_dummy'"
        ).rstrip()
        == "2\tnode1"
    )

    assert (
        node1.query("SELECT count() FROM merge_table PREWHERE id = 1").rstrip() == "1"
    )


def test_select_table_name_from_merge_over_distributed(started_cluster):
    node1.query("INSERT INTO local_table_2 VALUES (1, 'node1')")
    node2.query("INSERT INTO local_table_2 VALUES (2, 'node2')")

    node1.query("select _table == 'distributed_table' from merge_table")
    node1.query(
        "select * from (select _table == 'distributed_table' from merge_table limit 1)"
    )


if __name__ == "__main__":
    with contextmanager(started_cluster)() as cluster:
        for name, instance in list(cluster.instances.items()):
            print(name, instance.ip_address)
        input("Cluster created, press any key to destroy...")