Querying Incomplete Data over Extended ER Schemata

Details Querying Incomplete Data over Extended ER Schemata Querying Incomplete Data over Extended ER Schemata

2010-03-16

arxiv.org/abs/1003.3139v2

Computer Science

Databases

40 pages, 1 figure.

Scientific paper

Since Chen's Entity-Relationship (ER) model, conceptual modeling has been playing a fundamental role in relational data design. In this paper we consider an extended ER (EER) model enriched with cardinality constraints, disjointness assertions, and is-a relations among both entities and relationships. In this setting, we consider the case of incomplete data, which is likely to occur, for instance, when data from different sources are integrated. In such a context, we address the problem of providing correct answers to conjunctive queries by reasoning on the schema. Based on previous results about decidability of the problem, we provide a query answering algorithm that performs rewriting of the initial query into a recursive Datalog query encoding the information about the schema. We finally show extensions to more general settings. This paper will appear in the special issue of Theory and Practice of Logic Programming (TPLP) titled Logic Programming in Databases: From Datalog to Semantic-Web Rules.

Affiliated with

Also associated with

No associations

Rating

Querying Incomplete Data over Extended ER Schemata does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Querying Incomplete Data over Extended ER Schemata, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Querying Incomplete Data over Extended ER Schemata will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-245403