An integrated data processing system with two-tier data caching system and techniques for use thereof in a hybrid RDBMS and BDS computing environment are provided. In one aspect, the system is RDBMS-centric and uses two caches, one on the RDBMS side (1st tier) and the other on the BDS side (2nd tier). In another aspect, a DRDA wrapper on the BDS side enables the RDBMS to communicate with the BDS as if the BDS is another RDBMS. This is advantageous because the RDBMS already supports the DRDA protocol standard. In yet another aspect, the DRDA wrapper performs the data transformation needed when transferring cached objects between the RDBMS cache and BDS cache because RDBMS and BDS save data objects in different formats. This is advantageous because it offloads the computation from RDBMS to BDS therefore reducing the performance impact on RDBMS for its normal query and transaction processing.