An efficient method for queries execution in a multi-user environment

In a multi-user environment, multiple queries co-exist together in the system. Further, we observe that these queries usually share common sub-queries or reference common relations. By using cached results from earlier queries, better performance as well as faster evaluation of subsequent queries can be achieved. One promising concept that has been recently proposed is the cache-on-demand (CoD) schemes. CoD considers intermediate/final results of existing running queries as virtual caches, of which only the beneficial ones are materialized for incoming queries. In this paper, we propose a novel CoD-based strategy called Integrated-CoD. Unlike existing CoD-based schemes that operate in two phases, Integrated-CoD integrates the two phases into one. We evaluated the performance of Integrated-CoD against two known CoD-based schemes (Conform-CoD and Scramble-CoD). Our results show that Integrated-CoD offers superior performance at a marginal increase in optimization overhead.