How is SPFILE different from a PFILE (init.ora file)?
Unlike “init.ora” files, SPFILEs always reside on the server. Since they are in binary format, the only way change their content is to use the ALTER SYSTEM…….SCOPE=SPFILE | BOTH command. It is also not possible to specify the name and location of the SPFILE with the STARTUP command. You can either use the default SPFILE or use the pfile parameter SPFILE to point the instance to a non-default SPFILE. Dynamic changes made to initialization parameter value can be made persistent in the SPFILE since it can be updated directly by the server. Finally, all member instances of a Real Application Cluster database use single SPFILE as against using individual PFILEs.
