Abstract: An access structure analysis method is interspersed with the query optimization process. The method can determine the ideal combination of access structures, including both materialized views and indexes, for a given database workload. The interspersed structure analysis method can include advanced transformations like view merging, star transformation, bitmap access plans, query rewrite using materialized views, for example. The method may be performed using the query optimizer's rules as heuristics to guide the index candidate generation process.

Abstract: A method is provided for incrementally refreshing a materialized view after multiple operations on a row of a base table of the materialized view, by determining an equivalent operation for the multiple operations and refreshing the materialized view according to the equivalent operation. The method is applicable to a materialized view based on multiple base tables on which multiple operations have been performed. The step of determining the equivalent operation can include identifying rows for which an earliest operation is a DELETE operation, or rows for which a latest operation is an INSERT operation, or a combination of the two. The step of refreshing the materialized view includes performing an inverse operation of the equivalent operation to determine a pre-update state of the row, and refreshing the materialized view based on the pre-update state. Additional embodiments are provided which enhance the performance of materialized view refresh queries.