First Look: JDBC and InterSystems IRIS

Plus, if you are connecting to a local Windows machine (either using a hostname of localhost or an IP address of 127.0.0.1), then the connection automatically uses a special, high-performance local connection, called a shared memory connection. For more information about shared memory connections, see “JDBC: What’s Unique about Shared Memory Connections”.

The point of this document is to give you a taste of using JDBC with InterSystems IRIS without bogging you down in details, so we’ve kept this exploration simple. When you bring InterSystems IRIS to your production systems, though, there are many things you will need to do differently, such as in regard to (but not limited to) security. So be sure not to confuse this exploration of InterSystems IRIS with the real thing! The sources provided at the end of this document will give you a good idea of what’s involved in using JDBC with InterSystems IRIS in production.

The InterSystems IRIS JDBC driver is the core InterSystems IRIS Java component, and supports traditional relational (SQL) access. It also provides the connection mechanism for Java calls that use the InterSystems IRIS Native API, which accesses the data in its natively stored format. For Java integration based on objects, InterSystems IRIS also provides a separate feature — the InterSystems IRIS XEP component.

Taken all together, InterSystems IRIS provides a unique set of capabilities to use the same physical connection and transaction context to manipulate data using multiple paradigms: native, relational, and object-oriented. For more complex applications, InterSystems fully supports Hibernate. Enabling all these forms of connectivity — InterSystems IRIS XEP, Hibernate, and also the InterSystems IRIS Spark Connector — is the InterSystems IRIS JDBC driver.

As with other database platforms, a JDBC connection to a remote InterSystems IRIS instance is over TCP/IP. To maximize performance, InterSystems IRIS also offers a Java shared memory connection. Shared memory connections are available to Java applications running on the same Windows machine as an InterSystems IRIS instance.

A shared memory connection is a temporary device, backed virtual memory, which is shared by a JDBC client and an instance of InterSystems IRIS running on the same physical machine. Further, these connections do not require potentially expensive calls into the kernel network stack. By using a channel directly from the JDBC client to InterSystems IRIS, they provide the ultimate in low latency and high throughput for JDBC operations.

If shared memory connections are available, InterSystems IRIS uses them by default — and you can easily disable them. For now, shared memory connections are available for JDBC only on Microsoft Windows. In future releases of InterSystems IRIS, you will be able to use shared memory connections on other platforms, including Linux.

import java.sql.*;

public class JDBCSample {
    public static void main(String[] str) throws Exception {
        String url = "jdbc:IRIS://127.0.0.1:51773/USER";

        Class.forName("com.intersystems.jdbc.IRISDriver");
        Connection connection = DriverManager.getConnection(url,"_SYSTEM","SYS");
        // Replace _SYSTEM and SYS with a username and password on your system

        String createTable = "CREATE TABLE People(ID int, FirstName varchar(255), LastName varchar(255))";
        String insert1 = "INSERT INTO People VALUES (1, 'John', 'Smith')";
        String insert2 = "INSERT INTO People VALUES (2, 'Jane', 'Doe')";
        String query = "SELECT * FROM People";

        Statement statement = connection.createStatement();
        statement.executeUpdate(createTable);
        statement.executeUpdate(insert1);
        statement.executeUpdate(insert2);
        ResultSet resultSet = statement.executeQuery(query);
        System.out.println("Printing out contents of SELECT query: ");
        while (resultSet.next()) {
            System.out.println(resultSet.getString(1) + ", " + resultSet.getString(2) + ", " + resultSet.getString(3));
        }
        resultSet.close();
        statement.close();
        connection.close();
    }
}