To change an init.ora parameter, follow these steps.

1. Open the file called init<database_name>.ora. For example, if the database is called oraprod, then the file would be called initoraprod.ora. The file can be in a variety of places, but almost always somewhere in a subdirectory of the Oracle Installation directory on the server (also known as the ORACLE_HOME).
2. Find the parameter that you wish to change. The parameter may not be in the file. If not, the default value is being used by Oracle. Add the parameter if it is not in the file and needs to be a non-default value.
3. Comment out the line containing the current setting (in case the change needs to be undone). A line will be commented out (ignored by Oracle) if a pound sign (#) is placed at the beginning of the line
4. Add a new line with the same parameter with the new setting.

Example

# Doubled db_cache_size from 30000000 on 5/4/2003, change made by Jeff Jones.

# db_cache_size = 30000000

db_cache_size=60000000