Algorithms for Selecting Views and Indexes to Answer Queries

Abstract

In many contexts it is beneﬠcial to answer database queries using derived data called views. Using views in query answering is relevant in applications in information integration, data warehousing, web-site design, and query optimization. The problem of answering queries using views can be divided into a number of subproblems. The ﬠrst step in the process of view selection is to identify which view can be used to answer queries from the given set. The second step is to determine possible reformulations of the workload queries. The last step is choosing views that can be maintained appropriately and that minimize the processing time of the input query workload. In our work we address the problem of selecting and precomputing indexes and materialized views in a database system, with the goal of improving the processing performance for frequent and important queries. The focus of our work is to develop a uniﬠed quality-centered view- and index-selection approach, for a range of query, view, and index classes that are typical in practical database systems. To the best of our knowledge, we are the ﬠrst to adopt the solution-quality focus for this generic practical problem setting.