In Oracle Database Instant Client 19c, Instant Client and Instant Client Light are the only supported installation types.

The Instant Client installation type enables you to install only the shared libraries required by Oracle Call Interface (OCI), Oracle C++ Call Interface (OCCI), Pro*C, or Java Database Connectivity (JDBC) OCI applications.

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.

This Instant Client Light version 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.

Instant Client Light supports the following client character sets:

• Single-byte

  • US7ASCII

  • WE8DEC

  • WE8MSWIN1252

  • WE8MSWIN1252

  • WE8ISO8859P1

• Unicode

  • UTF8

  • AL16UTF16

  • AL32UTF8

• Instant Client Light can connect to databases having one of these database character sets:

  • US7ASCII

  • WE8DEC

  • WE8MSWIN1252

  • WE8ISO8859P1

  • WE8EBCDIC37C

  • WE8EBCDIC1047

  • UTF8

  • AL32UTF8

  The advantage of using Instant Client Light is that it has a smaller footprint than the regular Instant Client. The shared libraries, which an application must load, are only 34 MB as opposed to the 110 MB that regular Instant Client uses. Therefore, the applications use less memory.