Let us discuss about  to Optimal Flexiable Architecture  in oracle database Note :  

  $ORACLE_HOME =  /u01/app/oracle/product/11.2.0.3/db_1         
  $ORACLE_BASE =   /u01/app/oracle/product/11.2.0.3 

  1) SPfile:        

      - It means SERVER PARAMETER FILE    

      - It's always binary Format    

      - It's maintained by oracle server    

      - We can modify the parameters in spfile by using "ALTER SYSTEM " or "ALTER SESSION"  commands    

      - The default file location   is

 $ORACLE_HOME/dbs/spfiledbname.ora

2) Pfile :        

      - It always Text Format    

      - It's Maintained by Oracle DBA    

      - We can modify the parameters by operating system editor (using VI command )    

      - The default file location is

 $ORACLE_BASE/admin/dbname/pfile/initdbname.ora     

 

   Note:  Show Parameter spfile By issuing this command if the location is showed below the database was startup by " SPFILE" suppose this command not shown any files means the database was start up by "PFILE"  

3) Orapwd:           

      - It stores  the  password information about users who have  the administration rights  and enables to user connect  the remote servers    

      - ORAPWD utility  which helps to create password file for an oracle database    

      - The default file location in oracle database  is

 $ORACLE_HOME/dbs/Orapwddbname.ora

      - Check V$PWFILE_USERS to see who was granted OSDBA/OSOPER access.  

4) Database :     

      - The Database is a collection  of data which  contains data files ,control files ,redolog files     

      - The default location is

 $ORACLE_BASE/oradata/dbname

5) Tnsname.ora :      

      - It's establish the connections between  client  and server side     

      -The default   file location in oracle database  is

 $ORACLE_HOME/Network/Admin

6) Listener.ora:     

      - It's contains server side network configuration parameters     

      - The default file location in oracle database is

 $ORACLE_HOME/Network/Admin

      - It always listen client into server side