Oracle Instant Client allows you to run your applications without installing the standard Oracle client or having an Oracle home. 

The Tools Instant Client package is available on platforms that support the OCI Instant Client.

The Tools package contains several command-line utilities, including SQL*Loader, Data Pump Export, Data Pump Import, Original (classic) Export, and Original (classic) Import.

1. Instant client有两个版本 Basic Instant Client or Instant Client Light

1. Basic Instant Client

Basic Instant Client works with any NLS_LANG setting supported by the Oracle Database. It supports all character sets and language settings available in the Oracle Database.

1. Instant Client Light

The Instant Client Light (English) 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.

Instant Client Light is geared toward applications that use either US7ASCII, WE8DEC, WE8ISO8859P1, WE8MSWIN1252, or a Unicode character set.

There is no restriction on the LANGUAGE and the TERRITORY fields of the NLS_LANG setting, so the Instant Client Light operates with any language and territory settings. Because only English error messages are provided with the Instant Client Light, error messages generated on the client side, such as Net connection errors, are always reported in English, even if NLS_LANG is set to a language other than AMERICAN. Error messages generated by the database side, such as syntax errors in SQL statements, are in the selected language provided the appropriate translated message files are installed in the Oracle home of the database instance.

1. 从Oracle软件中提取Instant Client:

提取如下文件作Basic Instant Client使用：

Linux:

$ORACLE_HOME/instantclient/libociei.so

$ORACLE_HOME/lib/libnfsodm12.so

$ORACLE_HOME/bin/exp

$ORACLE_HOME/bin/imp

$ORACLE_HOME/bin/expdp

$ORACLE_HOME/bin/impdp

$ORACLE_HOME/bin/sqlldr

Windows:

%ORACLE_HOME%\instantclient\oraociei12.dll

%ORACLE_HOME%\bin\exp.exe

%ORACLE_HOME%\bin\imp.exe

%ORACLE_HOME%\bin\expdp.exe

%ORACLE_HOME%\bin\impdp.exe

%ORACLE_HOME%\bin\sqlldr.exe

提取如下文件作Light Instant Client使用：

Linux:

$ORACLE_HOME/instantclient/light/libociicus.so

$ORACLE_HOME/lib/libnfsodm12.so

$ORACLE_HOME/bin/exp

$ORACLE_HOME/bin/imp

$ORACLE_HOME/bin/expdp

$ORACLE_HOME/bin/impdp

$ORACLE_HOME/bin/sqlldr

Windows:

%ORACLE_HOME%\instantclient\light\oraociicus12.dll

%ORACLE_HOME%\bin\exp.exe

%ORACLE_HOME%\bin\imp.exe

%ORACLE_HOME%\bin\expdp.exe

%ORACLE_HOME%\bin\impdp.exe

%ORACLE_HOME%\bin\sqlldr.exe

1. 配置Instant Client

不需要配置ORACLE_HOME or ORACLE_SID环境变量

export LD_LIBRARY_PATH=/home/instantclient12_2:${LD_LIBRARY_PATH}

export PATH=/home/instantclient12_2:${PATH}

export NLS_LANG=AMERICAN_AMERICA.UTF8