Can anyone say when Oracle is justified? I have yet to encounter a problem the postgres or mysql didn't support but alas I have not worked on everything.
Support. You can properly find some solution to your issue with postgres online. Oracle can send an Oracle certified engineer who can solve your problem.
Consistency. Your enterprise depends on terabytes of hyper valuable information (Wallmart with their sales data), can you guarantee that you won't end up with corruption issues? Or that the next version will work with your system too?
That said as long as you make less than 20 mil/year, Oracle isn't likely to be the best solution.
Just a quick question: which engine do you use for your MySQL system?
InnoDB. I understand your support viewpoint but both of those dbs are opensource thereby leaving support open. From what I understand when the support comes into play is when you can sue the other party for not providing the service expected but there is company support for mysql and postgres so that still leaves me in the dark and I have never experienced corruption issues with either. Though my db experience is limited and I don't claim to be an expert.
When the ERP application you are installing has in it's specs
- Supported database: Oracle
I am sure a crack Postgres guy can bash and file that sucker to work. But the vendor will not support the result, and some places, some situations, that really counts for a great deal.
Oracle isn't selling databases. They're selling database support. Similar to how IBM operates - they make good stuff, but you're really not paying for the hardware. If you were, they'd be outrageously expensive compared to something built more simply - see Backblaze, for an example: http://blog.backblaze.com/2009/09/01/petabytes-on-a-budget-h... .
When you need multiple spatially distributed active/active write nodes (multiple masters...) you pretty much need Oracle RAC.
When confronted with the cost, you end up designing something where writes are pushed to a caching layer, which deals with an active/passive setup, with enough buffer to switch passive to active if something goes wrong.
Consistency. Your enterprise depends on terabytes of hyper valuable information (Wallmart with their sales data), can you guarantee that you won't end up with corruption issues? Or that the next version will work with your system too?
That said as long as you make less than 20 mil/year, Oracle isn't likely to be the best solution.
Just a quick question: which engine do you use for your MySQL system?