Optimization technique of queries with plural predicates for a topic map database

When a user submits a query to the topic map database, there are multiple ways to retrieve target elements. In the previous study, although cost based query optimization applied to the topic map database was proposed, it was limited to queries including a single predicate. In this paper, we propose cost based query optimization for queries consisting of plural predicates. We also evaluate the proposed cost by comparing it with the running time of queries submitted to TOME.