Kellyn Pot’vin-Gorman has a tough talk:
If we were to ask any DBA to separate the database in one cloud and the application tier in another without the context of a marketing announcement, they would look at us like we’d grown a third head. I’m incredibly surprised that anyone even considers the OCI Interconnect for this use, let alone the 150 that are currently using it. Oracle applications, like E-business Suite, Peoplesoft, JD Edwards and Hyperion are incredibly network latency sensitive and to recommend separating their tiers in two separate clouds just is alien to me. When we deploy these in Azure, we place all tiers in a proximity placement group to let Azure know that they are connected and this ensures that when a resource comes online after changes are made, redeployments, etc. the resources stay close to each other.
Definitely worth a read.