C++ Objects in Db2

In today's heterogeneous development environments, application programmers have the responsibility to segment their application data and store relational data in RDBMSs, C++ objects in OODBMSs, SOM objects in OMG persistent stores, and OpenDoc or OLE compound documents in document les. In addition, they must deal with multiple server systems with diierent query languages as well as large amounts of heterogeneous data. This paper describes SMRC, 1 an RDBMS extender that provides the ability to store objects created in external type systems like C++ or SOM in a relational database, co-resident with existing relational or other heterogeneous data. Using SMRC, applications can store and retrieve objects via standard SQL query language and invoke methods on the objects, without requiring any modiications to the original object deenitions. Furthermore, the stored objects fully participate in all the characteristic features of the underlying relational database, e.g., transactions, backup, and authorization. SMRC is implemented on top of IBM's DB2 Common Server for AIX relational database system and heavily exploits its User-Deened Types (UDTs), User-Deened Functions (UDFs), and Large Objects (LOBs) technology. In this paper, the C++ type system is used as a sample external type system to exemplify the SMRC approach, i.e., C++ objects are stored in relational databases. Similar eeorts are required for SOM or OLE objects. 1 SMRC stands for Shared Memory-Resident Cache; we pronounce ittsmarc]. SMRC is available on CompuServe under the GO DB2 area.