SPFILE

What SPFILE is?

• Binary file
• The term "binary file" is often used as a term meaning "non-text file".
• Initialization parameter file
• A server parameter file can be thought of as a repository for initialization parameters that is maintained on the machine running the Oracle Database server. It is, by design, a server-side initialization parameter file. 
• Initialization parameters are persistent
• Initialization parameters stored in a server parameter file are persistent, in that any changes made to the parameters while an instance is running can persist across instance shutdown and startup. 
• ALTER SYSTEM statements
• This arrangement eliminates the need to manually update initialization parameters to make persistent any changes effected by ALTER SYSTEM statements. It also provides a basis for self-tuning by the Oracle Database server.
• CREATE SPFILE statement
• A server parameter file is initially built from a text initialization parameter file using the CREATE SPFILE statement. (It can also be created directly by the Database Configuration Assistant). The server parameter file is a binary file that cannot be edited using a text editor.
• PFILE
• SPFILE is a binary file that contains the same information as the old PFILE.