Batch Insert r2dbc

[javiercj93]

Looks like bulk inserts are inserting 1 by 1 and not in batches.

I have created the following table:

CREATE TABLE IF NOT EXISTS  test
(
    `a` Int16,
    `b` Int16,
    `created` DateTime
)
ENGINE = MergeTree()
PARTITION BY (toYYYYMM(created))
ORDER BY (created)
TTL created + INTERVAL 13 MONTH;

If I try to do the following:

    public Mono<Void> saveAll(){
        return Mono.from(connectionFactory.create())
                .flatMapMany(conn -> execute(conn)).then();
    }

    private Publisher<? extends Result> execute(Connection conn) {
        return conn.createStatement("insert into test values (:a, :b, :created)")
                .bind("a",1)
                .bind("b", 2)
                .bind("created", LocalDateTime.now())
                .add()
                .bind("a",5)
                .bind("b", 6)
                .bind("created", LocalDateTime.now())
                .execute();
    }

When checking the logs, I can see that 2 connections are established and inserts are run independently so it is not acting as a batch insert.

2024-09-02T10:43:28.253Z DEBUG 49005 --- [ckHouseWorker-1] com.clickhouse.client.AbstractClient     : Connection established: com.clickhouse.client.http.HttpUrlConnectionImpl@1f010075
2024-09-02T10:43:28.253Z DEBUG 49005 --- [ckHouseWorker-1] c.c.client.http.ClickHouseHttpClient     : Query: insert into `default`.test values (1, 2, 1725273808)
2024-09-02T10:43:28.254Z DEBUG 49005 --- [ckHouseWorker-2] com.clickhouse.client.AbstractClient     : Connection established: com.clickhouse.client.http.HttpUrlConnectionImpl@35e8f1b6
2024-09-02T10:43:28.254Z DEBUG 49005 --- [ckHouseWorker-2] c.c.client.http.ClickHouseHttpClient     : Query: insert into `default`.test values (5, 6, 1725273808)

Am I doing something wrong or is this the intended behaviour?

I have also tried using this approach but same behaviour

return conn.createBatch()
    .add("insert into test values (1, 2, '2024-01-17 00:00:00')")
    .add("insert into test values (5, 6, '2024-01-17 00:00:00')")
    .execute();

I am using clickhouse-r2dbc version 0.6.4.

[chernser]

Good day, @javiercj93! Thank you for reporting! We will look into it.

[eyal-mishor]

I am using clickhouse-r2dbc version 0.7.0 and see the issue too.

Looks to me as a critical issue since you can't really use r2dbc for batch inserts (the rows are inserted into different DB parts instead of a single part)

[chernser]

@eyal-mishor I agree - will try to look as soon as possible.

[crowcrow]

Observed this behavior in clickhouse-jdbc v0.7.x, while 0.6.x seems to work as expected