【摘要】 准确及时地获取地震前兆数据是开展地震短临预报和科学研究的重要基础。文中在详尽分析Oracle高级队列技术原理的基础上,给出了数据传输模型;分析了地震前兆数据的特点和传输要求;对比了已有的数据传输手段,如高级复制、E-mail,FTP等。通过PL/SQL语言编程实现了运用Oracle高级队列技术传输地震前兆数据的实例,认为利用Oracle高级队列技术进行地震数据传输是完全可行的,非常适合在地震业务处理系统中使用,为“十五”“中国地震信息服务系统”项目建设提供了一种新的数据传输手段。更多还原

【Abstract】 As far as the seismological research is based on observation, huge seismic precursor data are produced at earthquake stations. It is vital to send them precisely and betimes. During the period of the Ninth Five-Year Project of China Seismological Bureau, several methods were applied to transmitting seismic precursor data, such as advanced replication, FTP, E-mail and etc. The advanced replication is used more extensively than others. But data are often lost by advanced replication. So a new transmission method has to be found to meet the need. This paper presents the advanced queuing method for transmitting seismic precursor data. Advanced queuing has a unique database-integrated message queuing feature built on the Oracle Streams information integration infrastructure. With Advanced Queuing, message queuing operations can be performed in the way similar to SQL operations from the Oracle database. Message queuing functionality allows applications of Oracle database to communicate asynchronously via messages in AQ queues. With the development in seismic precursor observation in China, more knowledge on the characteristics of seismic precursor data has been gained, for instance the data sources are complex, the data structure is diversified, the data sampling rate is not consistent. In order to transmit seismologic precursor data, a standard data structure needs to be created. The transmission is either point to point or point to multi-points. The system is programmed by PL/SQL. Both the sending host and the receiving one are installed with Oracle9i version. The result shows that it can transmit seismic precursor data from earthquake station to provincial center safely and reliably by using advanced queuing. It also has additional advantages compared with before. Firstly, it can assign priority to data, and then transmit the urgent data of higher priority; Secondly, it is easy to manage the advance queue with Oracle Enterprise Manager. But the network bandwidth is still the bottleneck of the transmission.更多还原