Database range constraint that is dynamically limited by data in the database

摘要

A dynamic range constraint is defined that has one or more limits that are computed from data residing in the database. In a first embodiment, a dynamic range constraint is defined for a database column that includes at least one limit that is computed from data within that column. In a second embodiment, a dynamic range constraint is defined for a database column that includes at least one limit that is computed from data in a different database column. The limits may be computed using any suitable heuristic or criteria, including statistical analysis of the data in the database. In this manner a range constraint for a column may evolve automatically as the data in the database changes.