A Separate Oracle Database at work

It looks like the hardening was a little to hard. Oracle does need some access to the server. You can revert back the chmods for ping, Oracle rdbms does not need it. /tmp/ is not required, a usable location for tmp is, mostly for scripting. The rdbms has it's own tricks and storage for sorts.

Never install Oracle as root; use the root.sh at the end of the installation to do the system tweeks required. On some platforms there is a root pre script that should run before installation. The Oracle installation scripts refuse to run using the root account and can be run using any other account.

The access to some server config files has been made a little too tight for the install user to check the prerequisites. If you know they are ok, it's ok. Proving they are ok is a little easier when support issues arise. Check the group ownership of the critical config files and add the Oracle installation user to that group to give it read access.

Realistically, the requirement is crazy. Like all great crazy ideas, however, it is probably based on a nugget of potential reasonableness taken far out of context by people that have no understanding of the underlying rationale.

It can be reasonable to design a database schema such that no NULL values are allowed. If you do that, however, you are committing to a level of normalization where every non-required element is broken out into an separate table with an appropriate foreign-key reference back to the parent. It's not often done in practice but in cases where it makes sense to do, there can be benefits.

If you are going to design a database schema such that no NULL values are allowed, it makes no sense to allow let alone require magic values to indicate that something is unknown. That introduces all the problems that allowing NULL values has plus it adds additional code to check for the magic values that has to get repeated all over the place. It makes no sense to develop an API that requires magic values to be passed in regardless of the database design-- if you're going to hobble your code with checks for magic values, you really ought not let that insanity propagate out to other systems.