ob_java_connector_path

Description

ob_java_connector_path specifies the root path of the Connector JAR packages required for JNI (Java Native Interface) to access and execute external tables (such as HDFS external tables). This path is concatenated with the path specified by the ob_java_home parameter to form the JVM class loading path.

Privilege requirements

• Query the parameter

  sys tenant and all user tenants can query this parameter by using the SHOW PARAMETERS statement or the GV$OB_PARAMETERS view.

• Modify the parameter

  Only the sys tenant can modify this parameter. User tenants cannot modify this parameter.

Attributes

Usage notes

• This parameter is part of enabling the OceanBase Database Java environment to support JNI features such as HDFS external tables. It typically needs to be used together with the ob_enable_java_env, ob_java_home, and ob_java_opts parameters.
• Initialization time: The first initialization of the Java environment may take a long time, which may cause the first query on related external tables to time out. It is recommended to adjust the query timeout appropriately. Subsequent queries will not trigger re-initialization.
• Deployment consistency: In a multi-node deployment environment, ensure that the paths configured on all OBServer nodes point to the same existing directory to ensure normal functionality.
• Path requirements: The configured path should point to the directory where the Connector JAR packages are stored. If the delivered package directory contains entries such as current, hadoop, and a version directory (for example, vX.X.X; the actual version number depends on the OceanBase version), it is recommended to set ob_java_connector_path to the path of the current directory.
• Environment dependencies: Before using this feature, you need to properly install the Java environment (such as OpenJDK 8) on the server and configure the necessary environment variables (such as LD_LIBRARY_PATH pointing to the directory where libhdfs.so is located).

Examples

Set the path of the Java Connector to /home/admin/jni_packages/current.

obclient> ALTER SYSTEM SET ob_java_connector_path = '/home/admin/jni_packages/current';

References

• Enable Java environment parameter: ob_enable_java_env
• Set Java installation path parameter: ob_java_home
• Set JVM startup parameter: ob_java_opts
• For more information about ODPS external table features, see ODPS external table.