What is RDB Data Access Service?
RDB DAS provides provides transformation capability between SDO data graphs and relational databases and vise versa.
By using RDB DAS, applications developers avoid the details and complications of working directly with a relational database and also the complex transformation between relational rows/columns and SDO Data Object types/properties.
RDB DAS processes the SDO change summary and produces efficient update statements that only write to columns that have actually been modified.
The following diagram illustrates a DAS client. The client starts by reading a graph of data specified by some query. The client then makes modifications to the graph, possibly by adding elements, and then requests the DAS to push the changes back to the database.