JDBC Driver
This section describes the JDBC driver provided by Exasol to connect third party applications to Exasol.
System Requirements
JRE Requirement
The JDBC driver requires a Java runtime environment. You can use the driver on any platform with JRE version 1.8.0_282 or later.
Tested Systems
The driver has been tested on the following systems using the specified Java version with the latest available updates:
- Windows 10 (64 bit)
-
Java 1.8.0
-
Java 11.0.11
-
Java 17.0.2
For Windows systems, Microsoft .NET Framework 4.0 Client Profile™ should be installed on your system. There is an automatic installation wizard for it.
-
- Linux (64 bit)
-
Red Hat / CentOS 7, OpenJDK JVM 1.8.0
-
Red Hat / CentOS 8, OpenJDK JVM 1.8.0
-
OpenSUSE Leap 15.2, OpenJDK JVM 1.8.0
-
Debian 10, OpenJDK JVM 11.0.12
-
Ubuntu 18.04 LTS, OpenJDK JVM 11.0.13
-
Ubuntu 20.04 LTS, OpenJDK JVM 11.0.13
-
- macOS (64 bit)
-
macOS Mojave (10.14), JVM 16.0.1
-
macOS Catalina (10.15), JVM 16.0.1
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macOS Big Sur (11.6.1), JVM 1.8.0
-
macOS Monterey (12.0.1), JVM 1.8.0
-
- Free BSD (64 bit)
-
Free BSD 12.2, OpenJDK JVM 1.8.0
-
Download JDBC Driver
- Go to the Exasol Downloads page.
- In the Download JDBC Driver section, select the required file based on your OS, for examples:
- Windows:EXASOL_JDBC-<version>.msi
- Unix:EXASOL_JDBC-<version>.tar.Z
- Linux:EXASOL_JDBC-<version>.tar.gz
- Run the executable file downloaded, and follow the setup wizard to complete the installation.
Installing JDBC Driver
On Windows
The driver is installed as a .jar archive in the installation directory.
On Linux/Unix
The driver is included in the delivered .tgz file. Depending on the application this archive must be added to the search path for the Java classes (CLASSPATH).
All classes of the JDBC driver belong to the Java com.exasol.jdbc package. The main class of the driver is com.exasol.jdbc.EXADriver
License
Each driver package includes the latest version of the license for the driver. The license allows you to bundle the driver with third-party software, for example when creating plugins for a BI tool. For more details, refer to the license file which is located in the folder where the driver was installed.
Integrating JDBC Driver using Maven
The JDBC driver is also available in the Exasol Maven repository (https://maven.exasol.com). Add the following repository and dependency to the build configuration of your project (for example, pom.xml for Maven)
<repositories>
<repository>
<id>maven.exasol.com</id>
<url>https://maven.exasol.com/artifactory/exasol-releases</url>
<snapshots>
<enabled>false</enabled>
</snapshots>
</repository>
</repositories>
<dependencies>
<dependency>
<groupId>com.exasol</groupId>
<artifactId>exasol-jdbc</artifactId>
<version>7.1.0</version>
</dependency>
</dependencies>
Exasol URL
The JDBC Driver uses the following URL structure for Exasol:
jdbc:exa:<host>/<fingerprint>:<port>[;<prop_1>=<value_1>]...[;<prop_n>=<value_n>]
The following table explains the elements of the URL structure.
Element | Details |
---|---|
jdbc:exa | This prefix is necessary for the driver manager. |
<host>/<fingerprint>:<port> |
Defines the servers and the port of the Exasol cluster (for example, 192.168.6.11..14:8563). You can also have a hostname mapped to multiple IP addresses. When opening a connection, the driver will randomly choose an address from the specified address range. If the connection fails, the driver will continue to try all other possible addresses. You can also specify an IP range with a comma-separated list. For example:
|
<prop_i=value_i> |
Instead of a list you can also specify a file that contains a list (for example, //c:\mycluster.txt). The two slashes ("/") indicate that a filename is specified. An optional list of properties separated by a ";" follows the port, the values of which should be set when logging-in. These properties correspond with the supported Driver Properties and are described in the following section. The values of properties within the URL can only consist of alphanumeric characters. |
Example from a Java program
import java.sql.*;
import com.exasol.jdbc.*;
public class jdbcsample
{
public static void main(String[] args)
{
try { Class.forName("com.exasol.jdbc.EXADriver");
} catch (ClassNotFoundException e) {
e.printStackTrace();
}
Connection con=null;
Statement stmt=null;
try {
con = DriverManager.getConnection(
"jdbc:exa:192.168.6.11..14:8563;schema=SYS",
"sys",
"exasol"
);
stmt = con.createStatement();
ResultSet rs = stmt.executeQuery("SELECT * FROM CAT");
System.out.println("Schema SYS contains:");
while(rs.next())
{
String str1 = rs.getString("TABLE_NAME");
String str2 = rs.getString("TABLE_TYPE");
System.out.println(str1 + ", " + str2);
}
} catch (SQLException e) {
e.printStackTrace();
} finally {
try {stmt.close();} catch (Exception e) {e.printStackTrace();}
try {con.close();} catch (Exception e) {e.printStackTrace();}
}
}
}
The above code sample builds a JDBC connection to Exasol, that runs on servers 192.168.6.11 up to 192.168.6.14 on port 8563. User sys with the password exasol is logged-in and the schema sys is opened. After that, all tables in this schema are shown.
Supported Interfaces
Exasol provides the following interfaces:
-
EXADataSource
-
EXASocketFactory
EXADataSource
The JDBC driver provides a CommonDataSource interface called EXADataSource. Use EXADataSource to pass arguments using the setProperty() method. For example:
EXADataSource ds = new EXADataSource();
ds.setProperty("socketfactory", "myTool.MySocketFactory");
ds.setProperty("<User>", "<MyDBUser");
...
EXASocketFactory
The JDBC driver provides a SocketFactory interface called EXASocketFactory. With EXASocketFactory you can use the Exasol specific method createCustomSocket to connect with a set timeout for the connection. For example:
public abstract class EXASocketFactory extends SocketFactory {
public abstract Socket createCustomSocket(<InetAddressHost>, <Port>, <Timeout>) throws IOException;
When more than one host is specified in a connection string, the connect attempts to each of these hosts are made using the SocketFactory specified by the user and the timeout (if given) until one host is connected.
Supported Driver Standards
The JDBC driver supports JDBC 4.2 Core API. Detailed information about the supported interfaces are provided in the API Reference which you can find in the html folder of the driver installation directory. If you want to learn more about JDBC, see JDBC Basics.
The standard includes the following:
- Access to the driver through the DriverManager API and configuration of the driver using the DriverPropertyInfo interface.
- Direct execution of SQL statements as a prepared statement and in batch mode.
- Support of more than one open ResultSet.
- Support of the DatabaseMetaData and ResultSetMetaData metadata APIs.
The following features are not supported:
- Savepoints
- User-defined data types and the types Blob, Clob, Array, and Ref.
- Stored procedures
- Read-only connections
- The API ParameterMetaData
If the rowcount of a query exceeds 2147483647 (231-1), the JDBC driver will return the value 2147483647. This is because of the 32-bit limitation for this return value defined by the JDBC standard.
Supported Driver Properties
You can transfer the following properties to the JDBC driver through the URL. Property names are case sensitive.
Property | Value | Description |
---|---|---|
schema | String | Name of the schema that should be opened after login. If the schema cannot be opened, the login fails with a java.sql.SQLException. Default: no schema to open |
autocommit | 0=off, 1=on | Switches autocommit on or off. Default: 1 |
encryption | 0=off, 1=on | Switches automatic encryption on or off. Default: 1 |
kerberosservicename | String | Principal name of the Kerberos service. If nothing is specified, the name "exasol" will be used as default. |
kerberoshostname | String | Host name of the Kerberos service. If nothing is specified, the host name of the connections string will be used as default |
fetchsize | numeric, >0 | Amount of data in kB which should be obtained by Exasol during a fetch. The JVM can run out of memory if the value is too high. Default: 2000 The same can be achieved by using the function setFetchSize(). |
debug | 0=off, 1=on | Switches on the driver's log function. The driver then writes a log file named jdbc_timestamp.log for each established connection. These files contain information on the called driver methods and the progress of the JDBC connection. It can assist the Exasol Support in the diagnosis of problems. Due to performance reasons the logging should not be used in a productive system Default: 0 |
logdir | String | Defines the directory where the JDBC debug log files should be written to (in debug mode). Example: jdbc:exa:192.168.6.11..14:8563;debug=1;logdir=/tmp/my folder/;schema=sys Default is the application's current directory, which is not always transparent. That is why you should always set the log directory in debug mode. |
clientname | String | Defines the name of the client sent to the server. Default: "Generic JDBC client" |
clientversion | String | Defines the version of the client sent to the server. Default: empty ("") |
logintimeout | numeric, >=0 | Maximum time (in seconds) the driver waits for the database for a connect or disconnect request. Default is 0 (unlimited) |
connecttimeout | numeric, >=0 | Maximum time (in milliseconds) the driver waits to establish a TCP connection to a server. This timeout is used to limit the login time especially in case of a large cluster with multiple reserve nodes. Default: 2000 |
querytimeout | numeric, >=0 | Defines the time (in seconds) for a statement to run before it is automatically aborted. Default is 0 (unlimited) |
superconnection | 0=off, 1=on | Enables the user to execute queries even if the limit for active sessions (executing a query) has been reached. Note:
Default: 0 |
worker | 0=off, 1=on | The sub-connections for parallel read and insert have this flag switched on. Details and examples are available in an Exasol Knowledge Base Article. Default: 0 |
workertoken | numeric, >=0 | Is necessary to establish parallel sub-connections. Default: 0 |
connectionPoolSize | numeric, >=0 | Changes the maximum size of the connection pool. You can change it only once in the driver instance. Default: 64 Valid values: 0<connectionPoolSize<8192 |
snapshottransactions | 0=off, 1=on | The parameter defines the transaction Snapshot Mode for the connection. The default value for the parameter is 0. Set the parameter to 1 to enable Snapshot Mode for system tables. |
authmethod | String | Specifies the authentication method for OpenID. If the value for the parameter is accesstoken, the connection string will be "jdbc:exa:<host>:<port>;authmethod=accesstoken" and the password will be your OpenID Access Token. If the value for the parameter is refreshtoken, the connection string will be "jdbc:exa:<host>:<port>;authmethod=refreshtoken" and the password will be your OpenID Refresh Token. For more information, see Authentication using OpenID. |
validateservercertificate | 1=on, 0=off | Enables or disables the TLS server certificate validation. Default: 1 |
legacyencryption | 1=on, 0=off | Enables use of the old ChaCha encryption for the client-server communication and disables the new TLS encryption. Default: 0 |
socketfactory | String | Specifies the name of a SocketFactory that should be used while connecting to the server. |
enablenumerictypeconversion | 1=on, 0=off | The driver will show column decimal data types of a result set that can be converted to integer types as int or longint. Default: 1 |
fingerprint | String | Includes a fingerprint. For example: jdbc:exa:exadb1.example.com:8563;fingerprint=BA7816BF8F01CFEA414140DE5DAE2223B00361A396177A9CB410FF61F20015AD; To disable TLS validations, use NOCERTCHECK. NOCERTCHECK is case insensitive. It can occur after the host or port, or within the fingerprint argument. For example:
If the TLS validation fails and you trust the server, use the server's fingerprint. |
feedbackinterval | Integer | During a query the server sends feedback to the client at set intervals. This feedback:
Default: A feedback interval set too high may cause a long lag time before a command is canceled. |
keystore | String | To use a self signed certificate in JDBC, the certificate needs to be added to the system default keystore or you must create an keystore and add the certificate to the keystore. When the certificate is added to system default keystore, the JDBC driver will automatically load the certificate during the establishment of connection. If you create the keystore, you must specify the keystore in the connection string along with the keystore password and keystore type (optional). Default: None |
keystorepassword | String | If you specify the keystore in the connection string, you must include a keystore password. Default: None |
keystoretype | String | The keystore type is optional. Default: System keystore type |
Best Practices
Objective | Details |
---|---|
Memory of JVM | When operating on big tables, you can get problems if the specified memory for the JVM is not big enough. |
Reading big data volumes | Through the parameter fetchsize, you can determine the data volume which should be fetched from the database per communication round. If this value is too low, the data transfer may take longer to complete. If this value is too high, the JVM may run out of memory. The recommended fetch size is 1000-2000. |
Inserting data into the database | Instead of using single insert statements like "INSERT INTO t VALUES 1, 2, ..." you should use the more efficient interface of prepared statements and their parameters. Prepared statements achieve optimal performance when using parameter sets between 500 kB and 20 MB. Moreover you should insert the data by using the native data types. |
Unused resources | Unused resources should be freed immediately. For example, Prepared Statements through "close()". |
Connection servers | Don't specify any unnecessary wide IP address range. Since those addresses are randomly tried until a successful connection, the "connect" could take much time. |
Only use one fingerprint per connection string | If you include more than one fingerprint, the connection will fail. This not only includes multiple fingerprint arguments, but also includes adding the fingerprint in multiple locations within the connection string. For example, you cannot include the fingerprint after the host or port and in a fingerprint argument. Rewrite the connection string with only one fingerprint. |