During the post 11g upgrade steps, I discovered a new feature in 11g.
In the 11g database, you can now create a pfile/spfile from memory !
I was used to create a pfile from the current spfile in 10g, and offcourse create a spfile from the adjusted pfile...but now it's also possible to creaet a pfile from memory. The syntax is almost the same..
[oracle@ebs2 log]$ sqlplus '/ as sysdba'
SQL*Plus: Release 18.104.22.168.0 - Production on Wed Apr 16 17:06:02 2008
Copyright (c) 1982, 2007, Oracle. All rights reserved.
Oracle Database 11g Enterprise Edition Release 22.214.171.124.0 - Production
With the Partitioning, OLAP, Data Mining and Real Application Testing options
SQL> create pfile='/ebs/proddb/11.1.0/dbs/init_prod.ora' from memory;