Free, light-weight, and easily installed Oracle Database tools, libraries and SDKs
Oracle Instant Client enables development and deployment of applications that connect to Oracle Database, either on-premise or in the Cloud. The Instant Client libraries provide the necessary network connectivity and advanced data features to make full use of Oracle Database. The libraries are used by the Oracle APIs of popular languages and environments including Python, Node.js, Go, PHP and Ruby, as well as providing access for Oracle Call Interface (OCI), Oracle C++ Call Interface (OCCI), JDBC-OCI, ODBC and Pro*C applications. Tools included in Instant Client, such as SQL*Plus, SQL*Loader and Oracle Data Pump, provide quick and convenient data access.
Oracle Instant Client
What’s New
Oracle Linux has Instant Client RPMs
Instant Client RPM packages for Oracle Linux can now be installed from yum.oracle.com for Oracle Linux 8 and Oracle Linux 7. Older releases are available for Oracle Linux 8, Oracle Linux 7 and Oracle Linux 6.
Instant Client is available for Docker
Dockerfiles are available on GitHub.
Instant Client Features
Instant Client applications are cloud ready
Deploy applications using Instant Client in the cloud, or connect to a cloud database.
Whether your applications are in the cloud or on-premise, you can install Instant Client and connect to cloud databases. Follow the normal installation process for your operating system. Some cloud-specific references are shown below.
Oracle Instant Client provides the necessary Oracle Database client-side files to create and run OCI, OCCI, ODBC, and JDBC OCI applications. Useful command-line utilities including SQL*Plus, SQL*Loader and Oracle Data Pump are also available. Oracle Instant Client simplifies the deployment of applications by eliminating the need for an Oracle home on the client machines.
The storage space requirement of an OCI application running in Instant Client mode is significantly reduced compared to the same application running in a full client-side installation. A minimal install of Instant Client shared libraries can occupy less than 10% of the space of a full client-side installation. Finally, the Instant Client is easy to install.
Why use Instant Client?
Installation involves unzipping a few files, or installing RPM packages.
The Oracle Database client-side number of required files and the total disk storage are significantly reduced.
There is no loss of functionality or performance for applications deployed using Instant Client.
It is simple for independent software vendors to package applications.
A README file is included with the Instant Client installation. It describes the version, date and time, and the operating system the Instant Client was generated on.
OCI applications, by default, look for the OCI Data Shared Library, libociei.so (or Oraociei18.1.dll on Windows) in the runtime library search path (for example LD_LIBRARY_PATH on Linux, or PATH on Windows) to determine if the application should operate in the Instant Client mode. If this library is not found, then OCI tries to load the Instant Client Light Data Shared Library (see Table 2-3 and Table 2-4), libociicus.so (or Oraociicus18.1.dll on Windows). If the Instant Client Light library is found, then the application operates in the Instant Client Light mode. Otherwise, a full installation based on Oracle home is assumed.
Table 2-1 Instant Client Shared Libraries for Linux and UNIX
Linux and UNIX
Description for Linux and UNIX
Client Code Library
OCI Instant Client Data Shared Library
Oracle Notification Service (ONS) library
Light Weight IPC Library
Message Queue Light Library
The libraries libclntsh.so.18.1, libclntshcore.so.18.1, and libociei.so must reside in the same directory in order to use Instant Client.
Table 2-2 Instant Client Shared Libraries for Microsoft Windows
Microsoft Windows
Description for Microsoft Windows
Forwarding functions that applications link with
ONS library used by OCI internally
Oracle Database 18 c library names are used in the table and are current for Oracle Database release 18c, version 18.1.
In general, all OCI functionality is available to an application being run using the Instant Client, except that the Instant Client is for client-side operation only. Therefore, server-side external procedures cannot use Instant Client libraries.
For development you can also use the Instant Client SDK.
Install from ZIP Files, from RPMs, and from Oracle Universal Installer
Oracle Instant Client can be installed in several ways.
The Instant Client libraries can be installed by either choosing the Instant Client option from Oracle Universal Installer or by downloading and installing either the ZIP files or RPMs from the OCI page on the Oracle Technology Network website: Oracle Instant Client
To Download and Install the Instant Client Libraries from the Oracle Technology Network Website
The following steps are for the Linux, Unix, and Windows environments.
Become root by running su and entering the super-user password.
Change to the directory in which you want to install.
Uninstall any earlier installations.
Or, install each package with rpm.
Exit the root shell. No need to reboot.
If necessary, set the NLS_LANG environment variable to specify the language and territory used by the client application and database connections opened by the application, and the client’s character set, which is the character set for data entered or displayed by a client program. NLS_LANG is set as an environment variable on UNIX platforms and is set in the registry on Windows platforms. See Oracle Database Globalization Support Guide for more information on setting the NLS_LANG environment variable.
After completing the preceding steps you are ready to run OCI applications.
The OCI application uses the Instant Client when the OCI shared libraries are accessible through the operating system Library Path variable. In this way, there is no dependency on the Oracle home and none of the other code and data files provided in the Oracle home are needed by OCI.
Install the Instant Client from the Oracle Universal Installer
If you did a complete client installation (by choosing the Admin option in Oracle Universal Installer), the locations of the Instant Client shared libraries in a full client installation are:
oraociei18.dll library is in ORACLE_HOME\instantclient
To enable running the OCI application using Instant Client, copy the preceding libraries to a different directory and set the operating system shared library path to locate this directory.
All the libraries must be copied from the same Oracle home and must be placed in the same directory. Co-location of symlinks to Instant Client libraries is not a substitute for physical co-location of the libraries.
There should be only one set of Oracle libraries on the operating system Library Path variable. That is, if you have multiple directories containing Instant Client libraries, then only one such directory should be on the operating system Library Path.
Similarly, if an Oracle home-based installation is performed on the same system, then you should not have ORACLE_HOME/lib and the Instant Client directory on the operating system Library Path simultaneously regardless of the order in which they appear on the Library Path. That is, either the ORACLE_HOME/lib directory (for non-Instant Client operation) or Instant Client directory (for Instant Client operation) should be on the operating system Library Path variable, but not both.
To enable other capabilities such as OCCI and JDBC OCI, you must copy a few additional files. To enable OCCI, you must install the OCCI Library ( libocci.so.18.1 on Linux or UNIX and oraocci18.dll on Windows) in the Instant Client directory. For the JDBC OCI driver, in addition to the three OCI shared libraries, you must also download OCI JDBC Library (for example libocijdbc18.so on Linux or UNIX and ocijdbc18.dll on Windows). Place all libraries in the Instant Client directory.
On hybrid platforms, such as Sparc64, to operate the JDBC OCI driver in the Instant Client mode, copy the libociei.so library from the ORACLE_HOME/instantclient32 directory to the Instant Client directory. Copy all other Sparc64 libraries needed for the JDBC OCI Instant Client from the ORACLE_HOME/lib32 directory to the Instant Client directory.
Environment Variables for Oracle Instant Client
The ORACLE_HOME environment variable no longer determines the location of NLS, CORE, and error message files.
An OCI-only application should not require ORACLE_HOME to be set. However, if it is set, it does not affect OCI. OCI always obtains its data from the Data Shared Library. If the Data Shared Library is not available, only then is ORACLE_HOME used and a full client installation is assumed. Though ORACLE_HOME is not required to be set, if it is set, then it must be set to a valid operating system path name that identifies a directory.
If Dynamic User callback libraries are to be loaded, then as this guide specifies, the callback package must reside in ORACLE_HOME/lib ( ORACLE_HOME\bin on Windows). Set ORACLE_HOME in this case.
Environment variables ORA_NLS10 and ORA_NLS_PROFILE33 are ignored in the Instant Client mode.
In these examples, n is the time zone data file version number.
To determine the versions of small and large time zone files that are packaged in the Instant Client Data Shared Library, enter the following command to run the genezi utility:
If OCI is not operating in the Instant Client mode (because the Data Shared Library is not available), then ORA_TZFILE variable, if set, names a complete path name as it does in previous Oracle Database releases.
If TNSNAMES local naming parameters are used, then, as mentioned earlier, TNS_ADMIN directory must contain the TNSNAMES configuration files. If TNS_ADMIN is not set, then the ORACLE_HOME/network/admin directory must contain Oracle Net Services configuration files.
Database Connection Strings for Oracle Instant Client
See Database Connection Strings for complete information about database connection strings.
Oracle Database Net Services Administrator’s Guide chapter on «Configuring Naming Methods» for more about connect descriptors
SDK for Oracle Instant Client
The software development kit (SDK) is a set of development tools that allows the creation of applications can be downloaded from the Instant Client link URL on the Oracle Technology Network website:
The Instant Client SDK package has both C and C++ header files and a makefile for developing OCI and OCCI applications while in an Instant Client environment. Developed applications can be deployed in any client environment.
The SDK contains C and C++ demonstration programs.
On Windows, libraries required to link the OCI or OCCI applications are also included. Make.bat is provided to build the demos.
On UNIX or Linux, the makefile demo.mk is provided to build the demos. The instantclient_18_1 directory must be in the runtime library search path, for example LD_LIBRARY_PATH before linking the application. The OCI and OCCI programs require the presence of libclntsh.so and libocci.so symbolic links in the instantclient_18_1 directory. Beginning with Oracle Database 18c, version 18.1, Instant Client Basic and Basic Light ZIP files on Linux, Unix, and macOS now have the libclntsh and libocci symbolic links precreated.
The SDK also contains the Object Type Translator (OTT) utility and its classes to generate the application header files.
About Oracle Instant Client Light
The Instant Client Light version of Instant Client further reduces the disk space requirements of the client installation.
The size of the library has been reduced by removing error message files for languages other than English and leaving only a few supported character set definitions out of around 250.
Oracle’s Instant Client ODBC software is a standalone package that offers the full functionality of the Oracle ODBC driver (except the Oracle service for Microsoft Transaction Server) with a simple install.
The ODBC driver has Oracle’s standard client-server version interoperability, see Support Doc ID 207303.1. For example Instant Client ODBC 19c can connect to Oracle Database 11.2 or later.
Installing Oracle Instant Client Basic and Basic Lite
Instant Client ODBC requires the Oracle Instant Client Basic or Basic Light package (depending on your locale requirements) also be installed. Download the desired package from OTN for your operating system and follow the installation instructions on the download page. For example, unzip the package to C:\instantclient_19_3 on Windows, unzip to /opt/oracle/instantclient_19_3 on Linux or other platforms, or use yum to install the RPM packages on Linux.
More details on Oracle Instant Client is in the Oracle Call Interface Programmer’s Guide.
Installing Oracle Instant Client ODBC
On Linux and UNIX
1. Download Install the Instant Client Basic or Basic Light package as described above.
3. Install the unixODBC driver manager if it is not already available. Refer to the «Recommended unixODBC Driver Manager version» section in this document for more information.
4. Execute odbc_update_ini.sh from the Instant Client directory.
5. Set any Oracle Globalization variables required for your locale. See the Oracle Database Globalization Support Guide for more information. For example on Linux you could set export NLS_LANG=JAPANESE_JAPAN.JA16EUC to work in the JA16EUC character in Japanese.
On Windows
Environment setup for ODBC applications
An ODBC application has to load the Oracle Instant Client ODBC driver’s shared library file (see next section) to connect to Oracle Database. On Linux/Unix the directory path of the shared library should be set in the environment variable LD_LIBRARY_PATH, or platform equivalent. It can also be configured in /etc/ld.so.conf. On Windows it should be set in the PATH environment variable.
Refer to the topics Environment Variables for OCI Instant Client and Database Connection Strings in the Oracle Call Interface Programmer’s Guide for setting up the Database Connection string and related environment variables like TNS_ADMIN, TWO_TASK, LOCAL etc.
Contents of the Oracle Instant Client ODBC Package
Note: Backup the Oracle ODBC driver shared library and other files before patching them.
On Linux and UNIX Patching the Instant Client ODBC driver on Linux/UNIX can be done by generating the Instant Client ODBC package and Basic or Basic Light package in a patched ORACLE_HOME. The procedure for patching and generating Instant Client ODBC, Basic and Basic Light packages is given in the Oracle Call Interface Programmer’s Guide. These new packages should then be unzipped into the Instant Client directory that needs to be patched. This method of patching is recommended.
Alternatively the Oracle Instant Client ODBC driver can be patched by copying the files that are listed below from a patched ORACLE_HOME:
On Windows Patching the Instant Client ODBC driver on Windows can be done only by manually copying the ODBC driver shared library files and supporting library files from a patched ORACLE_HOME or from an unpacked Oracle Database Bundle patch. These should be copied into the Instant Client directory. Generating an Instant Client ODBC package is not available on Windows.
The files that must be copied to the Instant Client directory:
Note: While copying from the Oracle Database Bundle patch, some of the files above may be missing. This implies that those files are unchanged and do not need to be patched.
Uninstalling Oracle ODBC Instant Client
On Linux and UNIX
The procedure to uninstall Instant Client ODBC on Linux/UNIX is:
On Windows
The procedure to uninstall Instant Client ODBC on Windows is:
Recommended unixODBC Driver Manager versions for Linux/UNIX
Описанный в предыдущем разделе процесс установки ПО Oracle Client требует выполнения подготовительных действий, необходимых для установки регулярного программного обеспечения Oracle Database Server.
К счастью, инсталляция полного программного обеспечения Oracle Client для подключения к базе данных Oracle может требоваться не всегда. Новое программное обеспечение Oracle Instant Client позволяет запускать приложения без установки стандартного ПО Oracle Client или наличия каталога ORACLE_HOME. Программное обеспечение Oracle Client не обязательно инсталлировать на каждом компьютере, которому необходим доступ к базе данных Oracle. Все существующие приложения OCI, ODBC и JDBC будут работать с Instant Client (Мгновенный клиент). При желании с ним можно даже использовать интерфейс SQL*Plus.
Instant Client предоставляет следующие преимущества по сравнению с полномасштабным ПО Oracle Client.
Установка Instant Client
Чтобы установить новое программное обеспечение Instant Client и быстро подключиться к базе данных Oracle, выполните следующие действия.
Где скачать Oracle Instant Client
Как мы уже говорили, Instant Client является бесплатным и совершенно открыто распространяется корпорацией Oracle. Вы можете его скачать по этой ссылке. Как видите, клиент есть для различных операционных систем с различной битностью.
База данных Oracle Database для начинающих: основы базы данных
Чтобы получить доступ к базе данных Oracle с ПК, вначале на нем необходимо инсталлировать программное обеспечение Oracle Client. Программное обеспечение Oracle Client поставляется вместе с программным обеспечением Oracle Server. Кроме того, его можно загрузить также из сайта OTN (http://technet.oracle.com). Программное обеспечение Oracle Client доступно для загрузки отдельно. Хотя версии Oracle Server и Oracle Client не обязательно должны совпадать, в Oracle рекомендуют применять соответствующие версии ПО, чтобы можно было полностью воспользоваться преимуществами новых функциональных возможностей.
Версию Oracle Client можно выяснить, просмотрев вывод при вызове утилиты SQL*Plus, как показано в следующем примере:
Приведенный вывод команды SQL*Plus показывает, что в системе установлено программное обеспечение Oracle Client версии 11.1.0.6.0.
При установке программного обеспечения Oracle Client можно выбрать одну из четырех опций.
На заметку! Новая опция Instant Client описана в наших блогах в статье “Мгновенный клиент Oracle”.
Установка Oracle Client
Чтобы установить программное обеспечение Oracle Client, выполните следующие действия.
Совет. При наличии нескольких установок Oracle на ПК система может содержать также несколько файлов tnsnames.ora. Пользователь может оказаться не в состоянии подключиться к новой базе данных после добавления информации о конфигурации сети в файл tnsnames.ora, если используется не этот файл. Убедитесь, что в пути ПО Oracle Client указан нужный файл tnsnames.ora.
Использование переменной среды TWO_TASK
Использование имени Oracle Net можно обойти, устанавливая переменную среды TWO_TASK (в системе UNIX/Linux) или переменную среды LOCAL (в системе Windows).
Переменная TWO_TASK указывает строку подключения для подключения к удаленному компьютеру. Программа SQL*Plus проверит значение переменной среды TWO_TASK и автоматически добавит его в строку подключения, как показано в следующем примере:
Как только переменная среды TWO_TASK установлена, к базе данных mydb можно подключаться следующим образом:
Обратите внимание, что применять спецификацию sqlplus scott/tiger@mydb не пришлось, поскольку используется переменная TWO_TASK.
На сервере Windows следующие команды эквивалентны установке переменной среды TWO_TASK:
Описанный в предыдущем разделе процесс установки ПО Oracle Client требует выполнения подготовительных действий, необходимых для установки регулярного программного обеспечения Oracle Database Server.
Чтобы получить доступ к базе данных Oracle с ПК, вначале на нем необходимо инсталлировать программное обеспечение Oracle Client. Программное обеспечение Oracle Client поставляется вместе с программным обеспечением Oracle Server. Кроме того, его можно загрузить также из сайта OTN (http://technet.oracle.com). Программное обеспечение Oracle Client доступно для загрузки отдельно. Хотя версии Oracle Server и Oracle Client не обязательно должны совпадать, в Oracle рекомендуют применять соответствующие версии ПО, чтобы можно было полностью воспользоваться преимуществами новых функциональных возможностей.