Design And Implementation Of A Results Set Caching Scheme Based On The XML Database Query

With the XML application more and more widely, the description and storage of datamigrate to XML format. Research on XML data query and storage is also graduallyexpanded.The database based on XML data formart has appeared. In the database, queryoptimization is an important research direction. The cache technology is an effective way toimprovequeryspeed.Through the"hot"datacaching,wecan effectivelyimprovetheprocessingabilityandtheresponsespeedofthedatabaseandreducethetimeofqueryresultsreturned.We analyzed the fundamental cause of the large customer access request delay anddescribed how to use the principles of the cache to accelerate database access.According tothe characteristics of XML databases and XML data, we presented and implemented adouble-ended client-server cache based on XML database based on the analysis of theexisting XML database data query process. Through the analysising and implementation ofthe two important issues, the cache replacement policy and the cache coherencymaintaining. In the analysis of the current strengths and weaknesses of various mainstreamreplacement policy based on the algorithm, we present a cache replacement algorithmbased on calculating weights according to the characteristics of cache structure designed.The algorithm can effectively replace the data cache. According to the characteristics ofthe double-side cache, the paper designed and implemented a program based on demandrequest to maintain cache coherency. In the chche we can support the ACID properties ofthings effectively. When the data changes, We can maintain the consistency of the data inthe cache and in the server effectively, improve the query performance of servers, reduceaccess latency and improve the I/O performance of database system.Finally, we test the correctness and validity of the structure of this kind of cache. The testresults show that the structure of the cache can effectively improve the XML data queryefficiency.