Tuong Chanh Truong

System RX: one part relational, one part XML

This paper describes the overall architecture and design aspects of a hybrid relational and XML database system called System RX. We believe that such a system is fundamental in the evolution of enterprise data management solutions: XML and relational data will co-exist and complement each other in enterprise solutions. Furthermore, a successful XML repository requires much of the same infrastructure that already exists in a relational database management system. Finally, XML query languages have considerable conceptual and functional overlap with relational dataflow engines. System RX is the first truly hybrid system that comingles XML and relational data, giving them equal footing. The new support for XML includes native support for storage and indexing as well as query compilation and evaluation support for the latest industry-standard query languages, SQL/XML and XQuery. By building a hybrid system, we leverage more than 20 years of data management research to advance XML technology to the same standards expected from mature relational systems.

DB2 goes hybrid: integratng native XML and XQuery with relational data and SQL

Comprehensive and efficient support for XML data management is a rapidly increasing requirement for database systems. To address this requirement, DB2 Universal DatabaseTM (UDB) now combines relational data management with native XML support. This makes DB2® a truly hybrid database management system with first-class support for both XML and relational data processing as well as the integration of the two. This paper presents the overall architecture and design aspects of native XML support in DB2 UDB and its integration with the relational data-flow engine. We describe the new XML components in DB2 UDB and show how XML processing leverages much of the infrastructure which is used for relational data.

Capturing global transactions from multiple recovery log files in a partitioned database system

DB2 DataPropagator is one of the IBMs solutions for asynchronous replication of relational data by two separate programs Capture and Apply. The Capture program captures changes made to source data from recovery log files into staging tables, while the Apply program applies the changes from the staging tables to target data. Currently the Capture program only supports capturing changes made by local transactions in a single database log file. With the increasing deployment of partitioned database systems in OLTP environments there is a need to replicate the operational data from the partitioned systems. This paper introduces a system called CaptureEEE which extends the Capture program to capture global transactions executed on partitioned databases supported by DB2 Enterprise-Extended Edition. The architecture and the components of CaptureEEE are presented. The algorithm for merging log entries from multiple recovery log files is discussed in detail.

On the linkage of dynamic tables in relational DBMSs

Tables and operations over tables are at the center of the relational model and have been at the core of the Structured Query Language (SQL) since its development in the 1970s. As database applications have grown rapidly, the concept of tables has been generalized in database languages. The new generalized table concept in the SQL standard and in some commercial databases includes explicitly defined derived tables, such as user-defined temporary tables, transition tables, user-defined table functions, and table locators, that can be manipulated by users. We call them dynamic tables, because their entities exist only at run time. The challenges that these dynamic tables pose to existing relational engines lie in the linkage between the creation of the derived table and its references. In this paper, we describe a uniform framework for compile-time and run-time processing of dynamic tables. We also give a thorough explanation of how such a generic framework can be realized in existing relational database management systems, such as IBM DATABASE 2TM Common Server. Our experience with our prototype has shown the simplicity, generality, and efficiency of our approach.