pfile en ifile

[230173]

Can someone give me some expanation about the pfile and the ifile. What's the difference. Which one are the right pfile and ifile?
Can i move these files while the database is running.

Thanx

 

[rcurva]

They both point to the destination of your initSID.ora on startup. The difference is, ifile can be define as a parameter in your initSID.ora to point to the real destination of your initSID.ora while the pfile is used to explicitly use a specific initSID.ora on startup.

like:
startup pfile=$ORACLE_HOME/admin/SID/pfile/initSID.ora

For eample:
If you do not specify the pfile= with your startup command, the default init file used will be $ORACLE_HOME/dbs/initSID.ora where SID is the current value of ORACLE_SID. But if you have several instances in your server and you place special admin dirs for those instances you can put an ifile entry in your $ORACLE_HOME/dbs/initSID.ora file pointing to the actual location of you initSID.ora file.

ifile=$ORACLE_HOME/admin/SID/pfile/initSID.ora

Yes, you can move these files or even edit it while the DB is running.

 

[lfoata]

The pfile is the main config file and is usually name initSID.ora.
ifile is usually the configSID.ora file.

ifile is specified in pfile.

You can move these files when the database is running since they are read at startup and contains information that cannot be dynamically changed.

I suugest if you move initSID.ora that you create a symbolic link from $ORACLE_HOME/dbs to the new location. ex($ORACLE_HOME/admin/SID/pfile/).

Whatever parameters are in ifile could also be in pfile.