...here's an interesting question: if EnterpriseDB's main claim to fame is that you can run Oracle applications without change against Postgres Plus Advanced Server; and if Dataupia makes the same claim with respect to data warehousing, then can you run Dataupia against Postgres Plus Advanced Server?
I'm no Dataupia expert, but it seems pretty clear to me that the answer is no. The reason is very simple: EnterpriseDB's offering is a stand-alone database system that acts like Oracle, while Dataupia's system is a transparent system accessed through Oracle. (Or others, but I shan't spill any specific beans.) Both are Oracle compatible, just not in the same way.
And for that matter, ParAccel will be able to make the same claim (Oracle compatibility) before too long. Yet they achieve it in an entirely different way - query routing with their "AMIGO mode" option.
In summary: Not all Oracle-compatible systems are compatible in the same way. Don't get carried away with possible combinations.