Using the SQL engine server
- Last Updated: July 30, 2025
- 2 minute read
- DataDirect Connectors
- ODBC
- MongoDB 8.0
- Documentation
Some applications may experience problems loading the JVM required for the SQL engine because the process exceeds the available heap space. If your application experiences problems loading the JVM, you can configure the driver to operate with the SQL engine in a separate process with its own JVM.
The driver supports the following SQL engine modes:
- Broker mode: To efficiently manage memory and resources, the Broker
automatically starts and stops itself based on configuration settings. The Broker launches
the driver's in memory SQL engine service when a connection to the database requires the
SQL Engine to process SQL requests and return results. This mode eliminates the need for
the application to explicitly start and stop the service.
For details, see "Configuring the SQL engine server using the Configuration Manager" (Windows) or "Configuring Broker mode for the SQL engine server on UNIX/Linux."
- Server mode: The driver's SQL Engine runs in
its own JVM process instead of loading the JVM into the same process as the application.
Server mode requires the SQL engine server to be manually started and stopped.
For details, see "Configuring the SQL engine server using the Configuration Manager" (Windows) or "Configuring server mode using Java options" (UNIX/Linux).
- Direct mode: The driver operates with the SQL
Engine running as a sub-process to the application process that loaded the ODBC driver
library.
For details, see "Configuring the SQL engine server using the Configuration Manager" (Windows).
- Auto mode: The driver attempts to run in server
mode; however, if the SQL engine server is unavailable, the SQL engine will failover to
run in direct mode.
For details, see "Configuring the SQL engine server using the Configuration Manager" (Windows) or "Configuring server mode using Java options" (UNIX/Linux).
- Windows: The driver operates in server mode by default.
- UNIX/Linux: The driver operates in direct mode by default.
See the following sections for details on configuring the SQL engine server on your platform.