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

Abstract

DB2 DataPropagator is one of the IBM's 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.