Research And Exploiture Of The Integrated Query Tool For Distributed Heterogeneous Databases Based On Metadata

Entering the 21st century, the life sciences have developed rapidly. Scientists have tapped hundreds of types of biologic databases to reserve research results for effective and efficient research and analysis. In the course of actualizing and accomplishing the Human Genome Project, biological data show a rapid increase of exponential series, thus the integration the query for distributed heterogeneous autonomous databases becomes a major problem.We propose an integral scheme of data resource based on metadata in order to solve the current problem in query of biologic data. In our integral scheme, the metadata distributed in all databases will be integrated to one metadata database according to a metamodel standard. The integral scheme annotates the metadata using the ontology and actualizes the integrating query for biological databases through mapping the relationship among metadata, the definition of ontology, and the term of ontology. The final goal of the scheme is to solve the common problem of integrating data resources by building up a sharable integrating data platform, to form a database of a virtual center that faces the fixed topic, the focused metadata, and disturbed basic data, and thus to support relating researches in various fields.At present, our team has built relative metadata databases, tapped the tools to import and manage metadata. Based on the team project, this paper focuses mainly on the following.1. Analyzing the metadata and CWM metamodel and implementing the browser of the metadata.2. Designing relative modules to construct user schema, to map relations between the schema and metadata, and to support the query of the user.3. Analyzing the query conditions from the user and transferring the query based on the user schema into the query sentence based on the databases; integrating and clearing query results returned from databases, and outputting the result according the user schema.The author has finished the design of an archetypal tool system of to integrate distributing databases. The system could change the user's query condition into query sentences of the actual databases, which has actualized integrating query to the data and made preparations for the actualization of further complex queries.