A tuple-oriented bucket partition index with minimum weighted mean of interferential numbers for DAS models

Database-as-a-Service(DAS)model is a new data management model which allow users to outsource their data to database service providers(DSP). Since data is stored in cryptograph form at DSP, the query efficiency becomes a critical problem. Existing solutions for this problem concentrate mostly on cryptograph index technology. In this paper, according to queries weights of different tuples, we propose a method of creating cryptograph index using tuple-oriented bucket partition, which has minimum weight mean of interferential numbers. Combining ordinary attribute index with our tuple-oriented index, we propose a scheme of combi index, which can increase the query hit rate obviously. For the relational operations under our cryptograph index strategy, we propose an executing scheme and give a real example about the query process using our cryptograph index.