Pfile parameter of Oracle oradim

The default naming conventions for this file are:
Init $ Oracle_SID.ora (in Unix environment)
Init % ORACLE_SID %. ora (in Windows)

By default, it is placed in the following directory
$ ORACLE_HOME/dbs (Unix)
% ORACLE_HOME %/DATABASE (Windows)
This parameter file does not need to be placed in a specified location. When starting an instance, you can use the pfile = filename option on the startup command to set its location.

However, this file has two disadvantages:

1. This parameter file must be placed on the client that starts the database. This will cause a large area of parameter files to "Multiply" and make it difficult to maintain;
2. to modify a parameter permanently, you cannot use the alter system command to modify the parameter. You must also ensure that all parameter files that can be used to start the database are manually updated;

Therefore, Oracle introduces the Server parameter file (SPFILE), which must be placed on the service host itself and can be used as a unique source for obtaining database parameters. In addition, the alter system command can write values to spfile without having to manually search for and maintain all parameter files.
Therefore, we recommend that you use spfile to set your database without considering the above issues.

The default location is $ ORACLE_HOME/dbs:
If you manually create a database, it will be of great help:
The following is the initSID. ora file of a self-built library.
Cd $ ORACLE_HOME/dbs
1. [oracle @ emrep dbs] $ more initPOD. ora
Compatible = 10.2.0.1 <---- version number
Db_name = pod <----- Database Name
Instance_name = POD <------ Instance name
Sga_max_size = 500 m <------ sga size
Sga_target = 500 m <-------
Undo_tablespace = undo1 <----- roll back tablespace: Set to undo1
Undo_management = auto
Job_queue_processes = 10
Aq_tm_processes = 10
Background_dump_Dest =/u01/app/oracle/admin/POD/bdump
Core_dump_dest =/u01/app/oracle/admin/POD/cdump
User_dump_dest =/u01/app/oracle/admin/POD/udump
Control_files = '/u01/app/oracle/oradata/pod/diska/control01.ctl', '/u01/app/oracle/oradata/pod/diskb/control02.ctl'

Explanation of Oracle parameters and parameter files spfile/pfile

Explore the secrets of Oracle pfile and spfile