Integrity checking is a crucial issue, as databases change their instance all the time and therefore need to be checked continuously and rapidly. Decades of research have produced a plethora of methods for checking integrity constraints of a database in an incremental manner. However, not much has been said about when to check integrity. In this paper, we study the differences and similarities ...

This paper describes a technique for importing automatically an external relational schema into Pegasus, a heterogeneous, multidatabase system. The Pegasus data model is a functional object model which supports specialization, object-identity, and nested aggregation. The import algorithm generates the definition of a Pegasus schema which captures the semantics of a relational schema containing ...

This paper introduces the concept of local referential integrity according to which an object may only reference objects belonging to the same composite object. For example, in production planning an employee of some department may only be scheduled to work on machines belonging to the same department. Usually, such a constraint must be stated explicitly by a predicate as \add on" to a database...

A systematic cross-country analysis of e-commerce activity reveals that although physical infrastructure explains much of the variation in basic Internet use, e-commerce activity also depends significantly on the "rule of law" and, secondarily, on availability of credible payment channels such as credit cards. These results suggest that an institutional environment that facilitates the building...

A data warehouse stores materialized views over data from one or more sources in order to provide fast access to the integrated data, regardless of the availability of the data sources. Warehouse views need to be maintained in response to changes to the base data in the sources. Except for very simple views, maintaining a warehouse view requires access to data that is not available in the view ...

Loan servicers today face increasing regulatory and investor pressures to make sure they properly protect and preserve the integrity of their loan records. Data security and data integrity, unfortunately, are two often-overlooked aspects of loan servicing. Failure in either area is a recipe for reputation damage at best, and financial disaster, at worst. The goal of this paper is to provide loa...

The Resource Space Model (RSM) is a semantic data model based on orthogonal classification semantics for effectively managing various resources in interconnection environment. In parallel with the integrity theories of relational and XML-based data models, this keynote presents the integrity theory for the RSM, including the entity integrity constraints based on the key system of the RSM, the m...

The comparison of two data sets can reveal a great deal of information about the time-varying nature of an observed process. For example, suppose that the points in a data set represent a customer’s activity by their location in n-dimensional space. A comparison of the distribution of points in two such data se.ts can indicate how the customer activity has changed between the observation period...