Before creating an Oracle instance, make sure that you have Administrator's access rights in both your Oracle server database and the operating system installed on the server machine. If you still need to create an instance from the account in which you do not have Administrator's rights, and if your company's policy allows you to change the Oracle security, you can do the following: in the Sqlnet.ora file, add the # symbol before the Sqlnet.Authentication_Services = (NTS) parameter to comment it out. The default location of the Sqlnet.ora file will look similar to the following path:
\\<Oracle home folder>\Product\<Version*>\db_1\Network\Admin\
(* An example of the 'Version' folder name is 10.2.0)
You must have enough free disk space on the hard disk where the Oracle database is located to be able to create the new instance. The disk usage is as follows:
Oracle instance environment — 50 MB recommended
Oracle instance after running Oracle DB Setup — 80 MB recommended
Oracle instance after initializing a domain — 150 MB recommended
Before starting an Oracle database, you need to ensure that the RAM that this database occupies does not exceed the available RAM on your server. You can calculate the amount of RAM needed for the database by using the following Oracle parameters:
SHARED_POOL_SIZE (at least 10 MB)
JAVA_POOL_SIZE and LARGE_POOL_SIZE are additional parameters that affect the RAM that the Oracle database occupies. These parameters appear if you select certain options when running the Oracle Database Configuration Assistant using a custom installation type.
For the DB_BLOCK_SIZE parameter, make sure that the value is at least 8192.