OPTIMIZING QUERY OF THE DATABASE WEB VIEW USING CONSTRAINTS

The information and data on many large web sites are of structuredness or semi structuredness, which can be abstracted and then processed similarly as relational database or object oriented database to raise the operation efficiency, especially the query efficiency. However, new techniques are required for querying the view of such abstracted structural or semi structural data. Due to the distribution of data, which normally exist in the form of HTML or XML, the access of the web becomes the main factor of the query expense. Therefore, the access of the web may be reduced through using the redundancy of the web database. A subset of the Araneus data model is used in this paper, and also the link constraint, inclusion constraint, scope constraint and several rules rewriting the relational algebraic expressions are used to optimize the query results.