Efficient Management of Active Databases
Abstract
We have made advances in the following areas: Data cubes: these recent data-warehouse products need a way to optimize the use of space by selecting some views to maintain permanently. We have identified the 'monotonicy' property choosing one view cannot increase the value of materializing another view as guaranteeing the existence of a polynomial-time competitive (guaranteed to come within a constant fraction of optimum) solution. In one important nonmonotone case, data cubes with indexes on views, we showed how to find a polynomial competitive algorithm. Self Maintenance of views: We have techniques for deciding whether or not a view that is defined by a conjunctive query can be maintained in the face of an update to a base relation, without issuing queries to one or more base relations. For a variety of situations, we showed how to express this 'self maintainability' condition as an SQL query. We also can take advantage of functional dependencies to simplify the test.
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 25, 1998
- Accession Number
- ADA344235
Entities
People
- Jeffrey D. Ullman
- Jennifer Widom
Organizations
- Stanford University