A DRDS instance consists of the compute layer and the storage layer resources. The compute layer is a distributed cluster that consists of multiple Distributed Relational Database Service (DRDS) server nodes and business data is stored in multiple instances attached to the DRDS instance. Currently, all DRDS instance are dedicated instances, .
DRDS primary instances are used for scaling of single-instance relational databases and can process real-time online transactions with high concurrency.
Dedicated instances offer exclusive physical resources.