An initialization parameter file is an ASCII text file containing parameters.

By changing parameters and values in an initialization parameter file, you can specify, for example:

• Amount of memory Oracle Database uses

• Whether to archive filled online redo logs

• Which control files currently exist

Every database instance has a corresponding initialization parameter file and an ORACLE_SID registry parameter that points to the system identifier for the instance.

The initialization parameter file name takes the form init.ora. A single instance might have several initialization parameter files, each having some differences that affect system performance.

• About the Location of the Initialization Parameter File
  Describes the location of the initialization parameter file.
• About Editing The Initialization Parameter File
  To customize Oracle Database functions, you may be required to edit the initialization parameter file.
• About Oracle Database Configuration Assistant Renaming init.ora
  When you create a database using Oracle Database Configuration Assistant (Oracle DBCA), a Server Parameter File (SPFILE) is created from the initialization parameter file, and the initialization parameter file is renamed.