Maintain A Method Based On Path Expressions Materialized View Incremental

In the current network information times, the mount of information is very large and coming from different data sources, information integration is an effective way to make good use of data on web. In order to use the information on web, we utilize XML which is a common data exchanging tools as public information media and to eliminate inconsistency from different data sources by wrapping it.With respect to analysis of large mount information that is represented by XML, the corresponding time of queries of users is very important and regard as first of business, because the efficiency of query is a significant standard of database technology and it is also urgent demand in practical data analysis. Therefore, it is important way that we improve the efficiency of querying analysis of XML data warehouse by constructing materialized views for common data.In the method of incremental maintenance of path-based views, Sawires and his follow men have analyzed and discussed, and have gotten good solutions. However, we will use many branches' information of tree modal of XML in practical applications and it may be have many overlapped path and redundant predicate tests. So we should construct many views to accelerate the corresponding time of queries. This paper proposes a general method of incremental maintenance of path-based views to maintain several views. When it comes to the circumstance of overlapped path and redundant predicate tests, this method is more effective than the way of Sawires and the details as follow.Firstly, the algorithm of incremental maintenance of path-based views decomposes predicate test of certain path nodes which pass through XPATH queries. Then, we do unified queries and calculations of decomposed tests and save large mount of time-consumed queries. Therefore, its effectiveness is greater than the method of Sawires.