An initialization parameter file is a text file that contains a list of initialization parameters. The file should be written in the client's default character set.
The following are sample entries in an initialization parameter file:
PROCESSES = 100 OPEN_LINKS = 12 GLOBAL_NAMES = true
The name of the initialization parameter file varies depending on the operating system. For example, it can be in mixed case or lowercase, or it can have a logical name or a variation of the name
init.ora. Also supplied is an
initdw.ora file, which contains suggested parameter settings for data warehouses and data marts. The database administrator can choose a different file name for the initialization parameter file.
Refer to your operating system-specific Oracle documentation for the default locations and filenames for initialization parameter files on your operating system. The initialization parameter file is read by the client-side tool used to start the server (such as SQL*Plus).
Sample initialization parameter files are provided on the Oracle distribution medium for each operating system. A sample file is sufficient for initial use, but you will probably want to modify the file to tune the database for best performance. Any changes will take effect after you completely shut down and restart the instance.