I'm trying to currently upgrade my production Oracle 11g database server to I've been told from Oracle support that what they recommend is to do a "Out-of-place" upgrade. My question is how safe is it to do a "Out of Place" upgrade on a production machine? This is my 1st attempt and obviously don't know Oracle very well.

I downloaded the two required files for which are 1 of 7 and 2 of 7 zip files for Linux 64-bit. My current database is running from:

[oracle@cq ~]$ echo $ORACLE_HOME
I have now created $ORACLE_HOME/db_2/ directory and unzipped the two files into the newly created 'db_2' directory. Now before I run the ./runInstaller to upgrade my database, I have some questions:

1. Is it safe? Can I harm my current installation doing this upgrade? I was told by Oracle that they recommend "Out-of-place" upgrades because it minimizes downtime and wont overwrite and of the current files in $ORACLE_HOME/db_1.

2. Once the new is installed in the new 'db_2' folder, how does all the data migrate from the current 'db_1' to the new 'db_2'? Do I need to manually modify the $ORACLE_HOME path somehow?