We can perform database upgrade from 18.104.22.168 to 22.214.171.124 in 2 ways
1. In-Place 2. Out-of-Place (Oracle's recommended approach)
In prior releases, how it worked
DB Upgrade 8i to 10g (Out-Of-Place)
We install Oracle binaries for 10g at new location, then use DBUA or catupgrd.sql script to upgrade DB. This is Out-of-Place migration (i.e. created new oracle home, from inventory perspective).
DB Upgrade 10.2.0.1 to 10.2.0.4 (In-Place)
Here we won’t install 10.2.0.4 patchset in new home (Oracle won’t let us do that, as it is a patch), but select the existing home to upgrade. We also keep a backup of original 10.2.0.1, as we may have to fail back.
As 126.96.36.199 is not a patch and full install. It does not allow us to install binaries in existing 188.8.131.52 home (i.e. In-Place). But as I mentioned above, we can perform both upgrades
Case of In-Place upgrade
It is mandatory to move/rename existing oracle home and then install new binaries in existing oracle home path (i.e. same physical location but new binaries). Then run the upgrade script. In case of failure, we can revert back to original home (provided we have backup of old 184.108.40.206 home).
Case of Out-of-Place upgrade
We need to install 220.127.116.11 in new home and run the upgrade script.
In both cases, we have to provision space for two oracle homes. In case of Out-of-Place upgrade it is mandatory. In case of In-Place migration it is good to have, but not mandatory.