ok,
the main problem is that managers do not factor in the revenue costs of hidden complexity and risk which arise.
If enterprise licences add £5,000 to the revenue cost, and an encryption licence adds £1,000, the dumb manager will go for the third party tool, on the erroneous assumption that it will save £4,000.
First, Only Oracle's built-in encryption can maintain a tablespace in encrypted format, whilst it is being used. A third-party tool can only encrypt a copy which was taken at some point in the past. It can also encrypt RMAN backup files, but again, only once they're frozen.
This means that your running db is unencrypted, even if your back-up pieces are. Built-in encryption allows (I believe) to only encrypt particular tables or columns, so fine-grained control is possible. None of these facilities can be achieved otherwise. Also, since such tools usually only work on OS files, you can't use ASM or OMF, as their activities would torpedo any such software. You've paid for ASM and OMF, so now you'll pay more for software which will prevent their use - only a manager could come up with such a notion. There may be other 'gotchas' lurking in the undergrowth, but I think the point is already made.
As to cost, if a third-party tool is used, it must be verified that it correctly interoperates with every version of Oracle, and every db you have in use, otherwise it is useless.
The users must remember to use it all the time on back-ups, or write software to do so, which costs time and money, requires documentation, and must be maintained and managed indefinitely, which costs even more money.
The software must interoperate with all versions of your RMAN backups, for the reasons mentioned above, and must be similarly maintained.
If any new version of Oracle is deployed, the whole thing has to be checked and verified for correct operation, yet again.
In short, the company is signing up to a massive maintenance, verification, testing and documentation exercise which lasts indefinitely.
If you use Oracle, then Oracle corporation guarantees backwards compatibility (otherwise it would go out of business). It guarantees interoperability with RMAN (so you can script this, just like everything else) and Oracle corporation does all the maintenance, bug fixing, patching and documentation required.
Also, there is the unquantifiable but significant risk of the third party software irretrievably scrambling a crucial tablespace. This could cost millions, and if it did, your company would be in deep trouble. If this happened as a result of Oracle software, you could sue Oracle for those millions (as they have deep pockets and certify their software). A small third-party company might not be worth pursuing. In any event, such a foul-up would undoubtedly constitute a priority 1 request, and Oracle would likely respond.
I really despair when managers think that there's nothing more to it than adding numbers up in a spreadsheet. This ignores management effort, risk, hidden complexity (which increases the likelihood of failure) and the burden of maintaining such software indefinitely.
Regards
T
