Welcome to DiSC 2002
SIGMOD 2001
PODS 2001
= PODS'01 Website
= SIGMOD/PODS'01 Plena
<<< = PODS'01 Papers>>>
= Invited Talks
= Award Talks
= Tutorials
SIGMOD RECORD 2001
CIKM 2001
CoopIS 2001
DASFAA 2001
DASFAA 2000
DBPL 2001
Data Engineering Bul
DEXA_EC-WEB 2001
DMKD 2001
DPDJ 2001
HYPERTEXT 2001
ICDE 2001
ICDM 2001
ICDT 2001
JCDL 2001
KDD 2001
KDD_EXPLORATIONS 20
KRDB 2001
MDM 2001
MIR 2001
MIS 2001
RIDE 2001
SBBD 2001
SIGIR 2001
SIGIR FORUM 2001
SSDBM 2001
SSTD 2001
TODS 2001
TIME 2001
VLDB 2001
VLDBJ 2001

On XML Integrity Constraints in the Presence of DTDs


Wenfei Fan and Leonid Libkin

  View Paper (PDF)  

Return to XML


Abstract

The paper investigates XML document specifications with DTDs and integrity constraints, such as keys and foreign keys. We study the consistency problem of checking whether a given speci cation is meaningful: that is, whether there exists an XML document that both conforms to the DTD and satisfies the constraints. We show that DTDs interact with constraints in a highly intricate way and as a result, the consistency problem in general is undecidable. When it comes to unary keys and foreign keys, the consistency problem is shown to be NP-complete. This is done by coding DTDs and integrity constraints with linear constraints on the integers. We consider the variations of the problem (by both restricting and enlarging the class of constraints), and identify a number of tractable cases, as well as a number of additional NP-complete ones. By incorporating negations of constraints, we establish complexity bounds on the implication problem, which is shown to be coNP-complete for unary keys and foreign keys.


DiSC'02 © 2003 Association for Computing Machinery