Computer Science – Databases
Scientific paper
2011-07-07
LMCS 7 (3:9) 2011
Computer Science
Databases
55 pages, 3 figures
Scientific paper
10.2168/LMCS-7(3:9)2011
Relational data exchange is the problem of translating relational data from a source schema into a target schema, according to a specification of the relationship between the source data and the target data. One of the basic issues is how to answer queries that are posed against target data. While consensus has been reached on the definitive semantics for monotonic queries, this issue turned out to be considerably more difficult for non-monotonic queries. Several semantics for non-monotonic queries have been proposed in the past few years. This article proposes a new semantics for non-monotonic queries, called the GCWA*-semantics. It is inspired by semantics from the area of deductive databases. We show that the GCWA*-semantics coincides with the standard open world semantics on monotonic queries, and we further explore the (data) complexity of evaluating non-monotonic queries under the GCWA*-semantics. In particular, we introduce a class of schema mappings for which universal queries can be evaluated under the GCWA*-semantics in polynomial time (data complexity) on the core of the universal solutions.
No associations
LandOfFree
Answering Non-Monotonic Queries in Relational Data Exchange 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 Answering Non-Monotonic Queries in Relational Data Exchange, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Answering Non-Monotonic Queries in Relational Data Exchange will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-417386