Oracle Universal Installer - Oracle 10g/11g Data and Database Management Utilities - page 300

OUI components
The next figure shows the main OUI components—the Oracle Inventory , the Install
log , the oraparam.ini file and the products.xml file, as well as other optional files
such as the staticports.ini and the response.rsp files.

Oracle Inventory Location

Unix : /etc/oralnst.loc or /var/opt/oracle/oraInst.loc
Windows : HKEY_LOCAL_MACHINE\SOFTWARE\ORACLE\
inst_loc

staticports.ini

products.xml

*.rsp files

Oracle Inventory

oraparam.ini Install log

A brief description of each component is as follows:

Oracle Inventory : OUI manages a repository named Oracle Inventory. This is where
Oracle keeps track of what is installed on the target machine. There is a single Oracle
inventory for each host. The Oracle Inventory consists of a set of files whose location
is kept in the oraInst.loc file (Unix like OS) or in the inst_loc (Windows) registry
entry. The Oracle inventory has gone through an evolutionary process, and back
in version 9.2.0.4.0 a major format change took place. The format used on releases
prior to 9.2.0.4.0 is not compatible with the format that came thereafter, so mixing
the inventory with old versions is not possible.