Prepare Oracle client for an ArcView database connection

Last Published: April 25, 2020



You can add tables from an Oracle database to ArcView. However you must correctly configure the Oracle client in order to make a connection. This document discusses how to configure the Oracle client.


· The following environment variables MUST be defined on the computer where ArcView is installed:

¤ TNS_ADMIN - The path to your tnsnames.ora file.

The Service Name entries in the tnsnames.ora file describe the location of the database, the networking protocol, and other necessary connection information. Service Names (or database aliases) are created by the database administrator.

¤ ORACLE_HOME - The path to the installation directory for Oracle Client (OCI) on the local machine.

You can forgo installing the Oracle Client on the local machine and set ORACLE_HOME to the installation directory for Oracle Server, or the installation directory of Oracle Client on another computer. While this will work in most cases, this configuration is not supported by Oracle or ESRI; use it at your own risk.

· The following environment variables are optional. It is possible to connect without them, but they MUST be defined on the local machine in order for your configuration to be supported by Oracle or ESRI.

¤ TWO_TASK - The Service Name (or database alias) in the tnsnames.ora file that you will be connecting to, or the one you will be connecting to most frequently.

This variable set a default service. All that is required for the connection string when logging in is username/password. If the user wishes to connect to a different service, the connection string must be in the form of username/password@. If TWO_TASK is not set, the connection string must always include the service. In order for the configuration to be supported by Oracle or ESRI, this variable must be set to a service listed in the tnsnames.ora file.

¤ ORACLE_SID - The Oracle System ID for the Oracle Server. This should be the same as the value for the SID parameter in the tnsnames.ora file for the Service defined by the TWO_TASK variable.

Article ID:000001519

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