The Research And Implementation Of The Sources' Log Reading And Querying Services System Based On Oracle Database

Using the software architecture of the Integrator combined with Monitor in the data integration, the integration system has intelligent and continuous information support ability. It means the Monitor system notifies and transmits data changes of the source to the Integrator actively and continuously. Effectively, timely and reliably detecting of data change in the information source database is the key of implementing this kind of integration system.Reading and analyzing the transaction log of the database is one of the important methods in data change detecting. In the Oracle database system, there are two forms of log files: the online redo log and the archived log. The paper detects the data change of the information source using the method of reading the archived log of the Oracle database. This work bases on the research of the original Oracle online log reading module in the Monitor system, through studying the operations of the Oracle log system and the differences between two kinds of log reading, and implements the archived log reading which is more universal. It separates the log reading module and the log analysis module, builds up the information source log reading and querying services system that can run independently and maintain by itself. According to the needs of practical applications, the system implements two layouts of local reading and remote reading, and the concurrent log reading. And the management of the archived log files is also implemented.