NonStop Server for Java (NSJ) Programmer's Guide (NSJ 2.1+)

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Accessing NonStop SQL/MX Databases
The JDBC Driver for NonStop SQL/MX (JDBC/MX) implements the JDBC technology that supports JDBC 2.1 Data
Access API. The JDBC/MX driver enables Java applications to use Compaq NonStop SQL/MX to access Compaq
NonStop SQL databases. This section contains information specific to the JDBC/MX driver only. To obtain detailed
information on the standard JDBC API, you should download the JDBC API documentation provided by Sun
Microsystems (http://java.sun.com/products/jdbc/index.html).
This section describes the following subjects:
JDBC/MX Architecture●
Connection to SQL/MX●
Transactions●
SQL Object Naming and Mapping●
JDBC/MX Compliance●
JDBC/MX Architecture
The JDBC/MX driver is a Type 2 driver; it employs proprietary native APIs to use SQL/MX to access NonStop SQL
databases. The native API of SQL/MX cannot be called from client systems. For this reason, the JDBC/MX driver runs
on Compaq NonStop Himalaya servers only.
The JDBC/MX driver is best suited for a three-tier model. In the three-tier model, commands are sent to a middle tier
of services, which then sends the commands to the data source. The data source processes the commands and sends the
results back to the middle tier, which then sends them to the user. The middle tier makes it possible to maintain control
over access and the kinds of updates that can be made to corporate data. Another advantage is that it simplifies the
deployment of applications. Finally, in many cases, the three-tier architecture can provide performance advantages.
The following figure illustrates a three-tier architecture for database access:
Architecture of the JDBC Driver for SQL/MX