The Concept of Error in a Database: An Application of Temporal Databases

The existing database models do not capture the difference between updates intended to make changes and corrections. The information about errors is external to the database and such information cannot be queried. We give a model to capture the concept of error in a database. The model consisting of 2-dimensional temporal relations is a consistent extension of the classical relational model as well as our l-dimensional temporal relational model. To circumvent the identity of an object from becoming corrupt due to the presence of errors, we make a copy of the correct identity and permanently glue (anchor) it to the object. The transition from the l-dimensional case to the 2-dimensional case is complex, but most of this complexity is absorbed by the system and not passed on to the user. This paper is a promising application of temporal databases to main stream databases