Employing integrity constraints for query modification and intensional answer generation in multi-database systems

Author(s):  
M. M. Fonkam ◽  
W. A. Gray
Author(s):  
Harith T. Al-Jumaily ◽  
Dolores Cuadra ◽  
Paloma Martínez

In the context of database, we believe that MDD (Model-Driven Development) (OMG, 2006) is a very ambitious task because we find that when applying database development methodologies such as (Elmasri, et al., 2007), there are processes devoted to transforming conceptual into logical schemata. In such processes, semantic losses are produced since logical elements are not coincident with conceptual elements. A correct constraints transformation is necessary to preserve the semantics that reflects the Universe of Discourse. The multiplicity constraint, also called cardinality constraint, is one of these constraints that can be established in a conceptual schema. It has dynamic aspects that are transformed into the logical model as certain conditions to verify the insertion, deletion, and update operations. The verification of these constraints is a serious and complex problem because currently database systems are not able to preserve the multiplicity constraints of their objects. To solve the modeling problem, CASE tools have been introduced to automate the life cycle of database development. These platforms try to help the database developers in different design phases. Nevertheless, these tools are frequently simple graphical interfaces and do not completely carryout the design methodology that they are should to support.


1995 ◽  
Vol 24 (2) ◽  
pp. 269-280 ◽  
Author(s):  
A. Prasad Sistla ◽  
Ouri Wolfson

2002 ◽  
pp. 17-65
Author(s):  
Laura C. Rivero ◽  
Jorge H. Doorn ◽  
Viviana E. Ferraggine

In Part I, this chapter surveys the state of the art of the semantic integrity constraints in some relational and object relational available database systems. In Part II, it also provides an overview of the SQL standard integrity issues and describes semantic integrity support in the following DBMSs: Oracle, IBM DB2, Informix, Sybase and PostgreSQL. The major differences and similarities among these systems are analyzed in relation to the definition, semantics and fidelity to the SQL standard prescriptions.


10.14311/286 ◽  
2001 ◽  
Vol 41 (6) ◽  
Author(s):  
M. Badawy ◽  
K. Richta

Supporting integrity constraints is essential for database systems. Integrity constraints are used to ensure that the data in a database complies with rules that have been set to establish accurate and acceptable information for a database. Triggers provide a very powerful and flexible means to realize effective constraint enforcing mechanisms. Implementing triggers based on constraint specifications follows some simple rules that are basically independent of a particular commercial database system. This paper gives these rules, which can be used to derive triggers from constraint specifications. A comparison of advantages of constraints and triggers is also given in this paper.


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