Java client and JDBC driver for ClickHouse. Java client is async, lightweight, and low-overhead library for ClickHouse; while JDBC driver is built on top of the Java client with more dependencies and extensions for JDBC-compliance.
Java 8 or higher is required in order to use Java client(clickhouse-client) and/or JDBC driver(clickhouse-jdbc). In addition, starting from 0.3.2, JDBC driver only works with ClickHouse 20.7 or above, so please consider to either downgrade the driver to 0.3.1-patch or upgrade server to one of active releases.
❗ IMPORTANT
Maven groupId ru.yandex.clickhouse
and legacy JDBC driver ru.yandex.clickhouse.ClickHouseDriver
have been deprecated and no longer receive updates.
Please use new groupId com.clickhouse
and driver com.clickhouse.jdbc.ClickHouseDriver
instead. It's highly recommended to upgrade to 0.3.2+ now for improved performance and stability.
Note: in general, the new driver(v0.3.2) is a few times faster with less memory usage. More information can be found at here.
Category | Feature | Supported | Remark |
---|---|---|---|
API | JDBC | ✅ | |
R2DBC | ❌ | will be supported in 0.3.3 | |
Protocol | HTTP | ✅ | recommended, defaults to java.net.HttpURLConnection and can be changed to java.net.http.HttpClient (faster but less stable) |
gRPC | ✅ | still experimental, works with 22.3+, known to has issue when using LZ4 compression | |
TCP/Native | ✅ | clickhouse-cli-client (wrapper of ClickHouse native command-line client) was added in 0.3.2-patch10, clickhouse-tcp-client will be available in 0.3.3 |
|
Compatibility | Server < 20.7 | ❌ | use 0.3.1-patch(or 0.2.6 if you're stuck with JDK 7) |
Server >= 20.7 | ✅ | use 0.3.2 or above. All active releases are supported. | |
Data Format | RowBinary | ✅ | RowBinaryWithNamesAndTypes for query and RowBinary for insertion |
TabSeparated | ✅ | Does not support as many data types as RowBinary | |
Data Type | AggregatedFunction | ❌ | limited to groupBitmap |
Array(*) | ✅ | ||
Bool | ✅ | ||
Date* | ✅ | ||
DateTime* | ✅ | ||
Decimal* | ✅ | SET output_format_decimal_trailing_zeros=1 in 21.9+ for consistency |
|
Enum* | ✅ | can be treated as both string and integer | |
Geo Types | ✅ | Point, Ring, Polygon, and MultiPolygon | |
Int*, UInt* | ✅ | UInt64 is mapped to long |
|
IPv* | ✅ | ||
Map(*) | ✅ | ||
Nested(*) | ✅ | ||
Object('JSON') | ✅ | supported since 0.3.2-patch8 | |
SimpleAggregateFunction | ✅ | ||
*String | ✅ | ||
Tuple(*) | ✅ | ||
UUID | ✅ | ||
High Availability | Load Balancing | ✅ | supported since 0.3.2-patch10 |
Failover | ✅ | supported since 0.3.2-patch10 |
<dependency>
<groupId>com.clickhouse</groupId>
<!-- or clickhouse-grpc-client if you prefer gRPC -->
<artifactId>clickhouse-http-client</artifactId>
<version>0.3.2-patch10</version>
</dependency>
// endpoint: protocol://host[:port][/database][?param1=value1¶m2=value2...][#tag1,tag2,...]
ClickHouseNode endpoint = ClickHouseNode.of("https://localhost"); // http://localhost:8443?ssl=true&sslmode=NONE
// endpoints: [defaultProtocol://]endpoint1[,endpoint2,endpoint3,...][/defaultDatabase][?defaultParameters][#efaultTags]
ClickHouseNodes endpoints = ClickHouseNodes.of("http://(https://explorer@play.clickhouse.com:443),localhost,(tcp://localhost?!auto_discovery#experimental),(grpc://localhost#experimental)?failover=3#test")
try (ClickHouseClient client = ClickHouseClient.newInstance(ClickHouseProtocol.HTTP);
ClickHouseResponse response = client.connect(endpoint) // or client.connect(endpoints)
// you'll have to parse response manually if using a different format
.format(ClickHouseFormat.RowBinaryWithNamesAndTypes)
.query("select * from numbers(:limit)")
.params(1000).executeAndWait()) {
// or response.stream() if you prefer stream API
for (ClickHouseRecord r : response.records()) {
int num = r.getValue(0).asInteger();
// type conversion
String str = r.getValue(0).asString();
LocalDate date = r.getValue(0).asDate();
}
ClickHouseResponseSummary summary = response.getSummary();
long totalRows = summary.getTotalRowsToRead();
}
<dependency>
<!-- please stop using ru.yandex.clickhouse as it's been deprecated -->
<groupId>com.clickhouse</groupId>
<artifactId>clickhouse-jdbc</artifactId>
<version>0.3.2-patch10</version>
<!-- use uber jar with all dependencies included, change classifier to http for smaller jar -->
<classifier>all</classifier>
<exclusions>
<exclusion>
<groupId>*</groupId>
<artifactId>*</artifactId>
</exclusion>
</exclusions>
</dependency>
// jdbc:(ch|clickhouse):[defaultProtocol://]endpoint1[,endpoint2,endpoint3,...][/defaultDatabase][?defaultParameters][#efaultTags]
String url = "jdbc:ch:https://play.clickhouse.com:443";
Properties properties = new Properties();
properties.setProperty("user", "explorer");
properties.setProperty("password", "");
// optional properties
properties.setProperty("client_name", "Agent #1");
...
ClickHouseDataSource dataSource = new ClickHouseDataSource(url, properties);
try (Connection conn = dataSource.getConnection();
Statement stmt = conn.createStatement();
ResultSet rs = stmt.executeQuery("show databases")) {
...
}
Use mvn clean verify
to compile, test and generate shaded packages if you're using JDK 8. To create a multi-release jar file(see JEP-238), please use JDK 11 or above and follow instructions below:
-
make sure you have
~/.m2/toolchains.xml
, for example:<?xml version="1.0" encoding="UTF8"?> <toolchains> <toolchain> <type>jdk</type> <provides> <version>11</version> </provides> <configuration> <jdkHome>/usr/lib/jvm/java-11-openjdk</jdkHome> </configuration> </toolchain> <toolchain> <type>jdk</type> <provides> <version>17</version> </provides> <configuration> <jdkHome>/usr/lib/jvm/java-17-openjdk</jdkHome> </configuration> </toolchain> </toolchains>
-
run
mvn -Drelease clean install
to build and install the artificat to local repositoryNote: if you need to build modules separately, please start with
clickhouse-client
, followed byclickhouse-http-client
andclickhouse-grpc-client
, and thenclickhouse-jdbc
andclickhouse-benchmark
.
To benchmark JDBC drivers:
cd clickhouse-benchmark
mvn -Drelease clean package
# single thread mode
java -DdbHost=localhost -jar target/benchmarks.jar -t 1 \
-p client=clickhouse-jdbc -p connection=reuse \
-p statement=prepared Query.selectInt8
It's time consuming to run all benchmarks against all drivers using different parameters for comparison. If you just need some numbers to understand performance, please refer to table below and some more details like CPU and memory usage mentioned at here(still have plenty of room to improve according to ranking at here).
By default, docker container will be created automatically during integration test. You can pass system property like -DclickhouseVersion=21.8
to specify version of ClickHouse.
In the case you prefer to test against an existing server, please follow instructions below:
- make sure the server can be accessed using default account(user
default
and no password), which has both DDL and DML privileges - add below two configuration files to the existing server and expose all ports for external access
- put
test.properties
under either~/.clickhouse
orsrc/test/resources
of your project, with content like below:clickhouseServer=x.x.x.x # below properties are only useful for test containers #clickhouseVersion=latest #clickhouseTimezone=UTC #clickhouseImage=clickhouse/clickhouse-server #additionalPackages=