Efficient View Self-Maintenance.
Nam Huyn · 1996
We revisit the problem of finding a maximal test that guarantees that a view can be maintained using only the view, its definition and the update, regardless of the actual database instance. These maximal tests, we call Complete Tests for View Self-Maintainability (abbrev CTSM), are also known in the literature as necessary and sufficient conditions for Conditionally Autonomously Computable Updates ([TB88]). This paper focuses on finding an efficient evaluation of self-maintainability (abbrev SM). Our working hypothesis is that at least for conjunctive-query (abbrev CQ) views (i.e. select-project-join views with only equality comparisons), SM evaluation can be separated into a view-definition-time portion where a maximal test is generated solely based on the view definition, and an update-time portion where the test is actually applied to the view and the update. We also conjecture that these tests can be expressed as queries over the view in some traditional query language. The obviou...