ODPI-C Installation

Overview

To use ODPI-C in your own project, download its source from GitHub. A sample Makefile is provided if you wish to build ODPI-C as a shared library. Otherwise, add the ODPI-C source code to your project. On Windows, Visual Studio 2008 or higher is required. On macOS, Xcode 6 or higher is required. On Linux, GCC 4.4 or higher is required.

Projects using ODPI-C require Oracle Client libraries to be installed. The libraries provide the necessary network connectivity allowing applications to access an Oracle Database instance. They also provide basic and advanced connection management and data features to ODPI-C applications.

The simplest Oracle Client is the free Oracle Instant Client. Only the “Basic” or “Basic Light” package is required. Oracle Client libraries are also available in any Oracle Database installation or full Oracle Client installation.

ODPI-C explicitly loads available Oracle Client libraries at runtime. This allows code using ODPI-C to be built only once, and then run using available Oracle Client 18, 12, or 11.2 libraries. If Oracle Client libraries are not found, the error “DPI-1047: Oracle Client library cannot be loaded” is raised.

On Windows, the Oracle Client libraries are first looked for in the same directory that the ODPI-C library (or application binary) is located in. If they are not found, then the Oracle Client library directory should be included in the PATH environment variable.

On non-Windows platforms, if no Oracle Client is located in the standard operating system search path (e.g. $LD_LIBRARY_PATH), then $ORACLE_HOME is searched.

The following sections explain how to ensure the Oracle Client is installed and configured correctly on the various platforms so that ODPI-C is able to find it.

ODPI-C has been tested on Linux, Windows and macOS. Other platforms should also work but have not been tested.

Oracle Client and Oracle Database Interoperability

ODPI-C can use Oracle Client 18, 12, or 11.2 libraries.

Oracle’s standard client-server network interoperability allows connections between different versions of Oracle Client and Oracle Database. For certified configurations see Oracle Support’s Doc ID 207303.1. In summary, Oracle Client 18 and 12.2 can connect to Oracle Database 11.2 or greater. Oracle Client 12.1 can connect to Oracle Database 10.2 or greater. Oracle Client 11.2 can connect to Oracle Database 9.2 or greater. The technical restrictions on creating connections may be more flexible. For example Oracle Client 12.2 can successfully connect to Oracle Database 10.2.

Since a single ODPI-C binary can use multiple client versions and access multiple database versions, it is important your application is tested in your intended release environments. Newer Oracle clients support new features, such as the oraaccess.xml external configuration file available with 12.1 or later clients, session pool improvements, call timeouts with 18 or later clients, and other enhancements.

The function dpiContext_getClientVersion() can be used to determine which Oracle Client version is in use and the function dpiConn_getServerVersion() can be used to determine which Oracle Database version a connection is accessing. These can then be used to adjust application behavior accordingly. Attempts to use some Oracle features that are not supported by a particular client/server combination may result in runtime errors. These include:

  • when attempting to access attributes that are not supported by the current Oracle Client library you will get the error “ORA-24315: illegal attribute type”
  • when attempting to use implicit results with Oracle Client 11.2 against Oracle Database 12c you will get the error “ORA-29481: Implicit results cannot be returned to client”
  • when attempting to get array DML row counts with Oracle Client 11.2 you will get the error “DPI-1050: Oracle Client library must be at version 12.1 or higher”

Linux

ODPI-C requires Oracle Client libraries, which are found in Oracle Instant Client, or an Oracle Database installation, or in a full Oracle Client installation. The libraries must be either 32-bit or 64-bit, matching your application and ODPI-C library (if one is created separately).

On Linux, ODPI-C first searches for a library called “libclntsh.so” using the standard library search order. If this is not found, it will then search for “libclntsh.so.18.1”, “libclntsh.so.12.1” and then for “libclntsh.so.11.1”. If no library is found, then $ORACLE_HOME/lib/libclntsh.so is checked. If no library is found there, then an error is returned.

Oracle Instant Client Zip

To run ODPI-C applications with Oracle Instant Client zip files:

  1. Download an Oracle 18, 12, or 11.2 “Basic” or “Basic Light” zip file: 64-bit or 32-bit, matching your application architecture.

  2. Unzip the package into a single directory that is accessible to your application. For example:

    mkdir -p /opt/oracle
    cd /opt/oracle
    unzip instantclient-basic-linux.x64-12.2.0.1.0.zip
    
  3. Install the libaio package with sudo or as the root user. For example:

    sudo yum install libaio
    

    On some Linux distributions this package is called libaio1 instead.

  4. If there is no other Oracle software on the machine that will be impacted, permanently add Instant Client to the runtime link path. For example, with sudo or as the root user:

    sudo sh -c "echo /opt/oracle/instantclient_12_2 > /etc/ld.so.conf.d/oracle-instantclient.conf"
    sudo ldconfig
    

    Alternatively, set the environment variable LD_LIBRARY_PATH to the appropriate directory for the Instant Client version. For example:

    export LD_LIBRARY_PATH=/opt/oracle/instantclient_12_2:$LD_LIBRARY_PATH
    
  5. If you intend to co-locate optional Oracle configuration files such as tnsnames.ora, sqlnet.ora or oraaccess.xml with Instant Client, then create a network/admin subdirectory, if it does not exist. For example:

    mkdir -p /opt/oracle/instantclient_12_2/network/admin
    

    This is the default Oracle configuration directory for applications linked with this Instant Client.

    Alternatively, Oracle configuration files can be put in another, accessible directory. Then set the environment variable TNS_ADMIN to that directory name.

Oracle Instant Client RPM

To run ODPI-C applications with Oracle Instant Client RPMs:

  1. Download an Oracle 18, 12, or 11.2 “Basic” or “Basic Light” RPM: 64-bit or 32-bit, matching your application architecture.

  2. Install the downloaded RPM with sudo or as the root user. For example:

    sudo yum install oracle-instantclient12.2-basic-12.2.0.1.0-1.x86_64.rpm
    

    Yum will automatically install required dependencies, such as libaio.

  3. If there is no other Oracle software on the machine that will be impacted, permanently add Instant Client to the runtime link path. For example, with sudo or as the root user:

    sudo sh -c "echo /usr/lib/oracle/12.2/client64/lib > /etc/ld.so.conf.d/oracle-instantclient.conf"
    sudo ldconfig
    

    Alternatively, set the environment variable LD_LIBRARY_PATH to the appropriate directory for the Instant Client version. For example:

    export LD_LIBRARY_PATH=/usr/lib/oracle/12.2/client64/lib:$LD_LIBRARY_PATH
    
  4. If you intend to co-locate optional Oracle configuration files such as tnsnames.ora, sqlnet.ora or oraaccess.xml with Instant Client, then create a network/admin subdirectory under lib/, if it does not exist. For example:

    sudo mkdir -p /usr/lib/oracle/12.2/client64/lib/network/admin
    

    This is the default Oracle configuration directory for applications linked with this Instant Client.

    Alternatively, Oracle configuration files can be put in another, accessible directory. Then set the environment variable TNS_ADMIN to that directory name.

Local Database or Full Oracle Client

ODPI-C applications can use Oracle Client 18, 12, or 11.2 libraries from a local Oracle Database or full Oracle Client installation.

The libraries must be either 32-bit or 64-bit, matching your application and ODPI-C library (if one is created separately).

  1. Set required Oracle environment variables by running the Oracle environment script. For example:

    source /usr/local/bin/oraenv
    

    For Oracle Database XE 11.2, run:

    source /u01/app/oracle/product/11.2.0/xe/bin/oracle_env.sh
    
  2. Optional Oracle configuration files such as tnsnames.ora, sqlnet.ora or oraaccess.xml can be placed in $ORACLE_HOME/network/admin.

    Alternatively, Oracle configuration files can be put in another, accessible directory. Then set the environment variable TNS_ADMIN to that directory name.

Windows

ODPI-C requires Oracle Client libraries, which are found in Oracle Instant Client, or an Oracle Database installation, or in a full Oracle Client installation. The libraries must be either 32-bit or 64-bit, matching your application and ODPI-C library (if one is created separately).

On Windows, ODPI-C looks for the Oracle Client library “OCI.dll” first in the directory containing the ODPI-C library (or application), and then searches using the standard library search order.

Oracle Client libraries require the presence of the correct Visual Studio redistributable.

Oracle Instant Client Zip

To run ODPI-C applications with Oracle Instant Client zip files:

  1. Download an Oracle 18, 12, or 11.2 “Basic” or “Basic Light” zip file: 64-bit or 32-bit, matching your application architecture.

  2. Unzip the package into a single directory that is accessible to your application, for example C:\oracle\instantclient_12_2.

  3. Set the environment variable PATH to include the path that you created in step 2. For example, on Windows 7, update PATH in Control Panel -> System -> Advanced System Settings -> Advanced -> Environment Variables -> System Variables -> PATH.

  4. If you intend to co-locate optional Oracle configuration files such as tnsnames.ora, sqlnet.ora or oraaccess.xml with Instant Client, then create a network\admin subdirectory, if it does not exist, for example C:\oracle\instantclient_12_2\network\admin.

    This is the default Oracle configuration directory for applications linked with this Instant Client.

    Alternatively, Oracle configuration files can be put in another, accessible directory. Then set the environment variable TNS_ADMIN to that directory name.

If you wish to package Instant Client with your application, you can move the Instant Client libraries to the same directory as the ODPI-C library (or application). Refer to the Instant Client documentation for the minimal set of Instant Client files required. There is no need to set PATH. This only works on Windows.

Local Database or Full Oracle Client

The Oracle libraries must be either 32-bit or 64-bit, matching your application and ODPI-C library (if one is created separately).

To run ODPI-C applications using client libraries from a local Oracle Database (or full Oracle Client) 18, 12, or 11.2 installation:

  1. Set the environment variable PATH to include the path that contains OCI.dll, if it is not already set. For example, on Windows 7, update PATH in Control Panel -> System -> Advanced System Settings -> Advanced -> Environment Variables -> System Variables -> PATH.

  2. Optional Oracle configuration files such as tnsnames.ora, sqlnet.ora or oraaccess.xml can be placed in the network/admin subdirectory of the Oracle software.

    Alternatively, Oracle configuration files can be put in another, accessible directory. Then set the environment variable TNS_ADMIN to that directory name.

macOS

ODPI-C requires Oracle Client libraries, which are found in Oracle Instant Client for macOS.

On macOS, ODPI-C first searches for a library called “libclntsh.dylib” using the standard library search order. If this is not found, it will then search for “libclntsh.dylib.18.1”, “libclntsh.dylib.12.1” and then for “libclntsh.dylib.11.1” before returning an error.

Oracle Instant Client Zip

To run ODPI-C applications with Oracle Instant Client zip files:

  1. Download the 18, 12, or 11.2 “Basic” or “Basic Light” zip file from here. Choose either a 64-bit or 32-bit package, matching your application architecture. Most applications use 64-bit.

  2. Unzip the package into a single directory that is accessible to your application. For example:

    mkdir -p /opt/oracle
    unzip instantclient-basic-macos.x64-12.2.0.1.0.zip
    
  3. Add links to $HOME/lib or /usr/local/lib to enable applications to find the library. For example:

    mkdir ~/lib
    ln -s /opt/oracle/instantclient_12_2/libclntsh.dylib.12.1 ~/lib/
    

    Alternatively, copy the required OCI libraries. For example:

    mkdir ~/lib
    cp /opt/oracle/instantclient_12_2/{libclntsh.dylib.12.1,libclntshcore.dylib.12.1,libons.dylib,libnnz12.dylib,libociei.dylib} ~/lib/
    

    For Instant Client 11.2, the OCI libraries must be copied. For example:

    mkdir ~/lib
    cp /opt/oracle/instantclient_11_2/{libclntsh.dylib.11.1,libnnz11.dylib,libociei.dylib} ~/lib/
    
  4. If you intend to co-locate optional Oracle configuration files such as tnsnames.ora, sqlnet.ora or oraaccess.xml with Instant Client, then create a network/admin subdirectory, if it does not exist. For example:

    mkdir -p /opt/oracle/instantclient_12_2/network/admin
    

    This is the default Oracle configuration directory for applications linked with this Instant Client.

    Alternatively, Oracle configuration files can be put in another, accessible directory. Then set the environment variable TNS_ADMIN to that directory name.

Other Platforms

To run ODPI-C applications on other platforms (such as Solaris and AIX), follow the same general directions as for Linux Instant Client zip files or Local Database. Add the Oracle libraries to the appropriate library path variable, such as LD_LIBRARY_PATH on Solaris, or LIBPATH on AIX.