producing xml documents with guaranteed “good” properties david w. embley brigham young...
Post on 21-Dec-2015
217 views
TRANSCRIPT
![Page 1: Producing XML Documents with Guaranteed “Good” Properties David W. Embley Brigham Young University Wai Y. Mok University of Alabama in Huntsville Sponsored](https://reader030.vdocuments.site/reader030/viewer/2022032704/56649d565503460f94a3514f/html5/thumbnails/1.jpg)
Producing XML Documents with Guaranteed “Good” PropertiesDavid W. Embley
Brigham Young University
Wai Y. MokUniversity of Alabama in Huntsville
Sponsored in part by the National Science Foundation under grant number IIS-0083127
![Page 2: Producing XML Documents with Guaranteed “Good” Properties David W. Embley Brigham Young University Wai Y. Mok University of Alabama in Huntsville Sponsored](https://reader030.vdocuments.site/reader030/viewer/2022032704/56649d565503460f94a3514f/html5/thumbnails/2.jpg)
“Good” ~ XNF
Motivation XML is for Information Exchange. What constitutes a “good” XML document for Information Exchange?
Principles XML Document Properties
A Few Large Trees. No Redundancy.
Information Modeling Create a conceptual model. Generate “good” XML.
XNF Align XML trees with natural hierarchies in the data. Base redundancy elimination on FDs, naturally occurring MVDs, and
inclusion dependencies (IDs).
![Page 3: Producing XML Documents with Guaranteed “Good” Properties David W. Embley Brigham Young University Wai Y. Mok University of Alabama in Huntsville Sponsored](https://reader030.vdocuments.site/reader030/viewer/2022032704/56649d565503460f94a3514f/html5/thumbnails/3.jpg)
Example: XNF
GradStudent
FacultyMember
Hobby
Program
Department
GradStudent
FacultyMember
Hobby
Program
Department
F D
S P H
H
( F D ( S P ( H )* )* ( H )* )*
Kelly CS Pat PhD Hiking Hiking Skiing Skiing
Tracy MS Hiking Sailing
Chris MS
Lynn Math Sailing
![Page 4: Producing XML Documents with Guaranteed “Good” Properties David W. Embley Brigham Young University Wai Y. Mok University of Alabama in Huntsville Sponsored](https://reader030.vdocuments.site/reader030/viewer/2022032704/56649d565503460f94a3514f/html5/thumbnails/4.jpg)
Example: More Trees Than Necessary
GradStudent
FacultyMember
Hobby
Program
Department
GradStudent
FacultyMember
Hobby
Program
Department
S P F D
H F
H
( S P F ( H )* )* ( D ( F ( H )* )*
Pat PhD Kelly Hiking CS Kelly Hiking Skiing Skiing
Tracy MS Kelly Hiking Math Lynn Sailing Sailing
Chris MS Kelly
![Page 5: Producing XML Documents with Guaranteed “Good” Properties David W. Embley Brigham Young University Wai Y. Mok University of Alabama in Huntsville Sponsored](https://reader030.vdocuments.site/reader030/viewer/2022032704/56649d565503460f94a3514f/html5/thumbnails/5.jpg)
Example: Redundancy
GradStudent
FacultyMember
Hobby
Program
Department
GradStudent
FacultyMember
Hobby
Program
Department
H
S P
( H ( S P )* )*
Hiking Pat PhD Tracy MS
Skiing Pat PhD
Sailing Tracy MS
S
H
F
( S ( H ( F )* )* )*
Pat Hiking Kelly Skiing Kelly
Tracy Hiking Kelly
Sailing Lynn
Chris
![Page 6: Producing XML Documents with Guaranteed “Good” Properties David W. Embley Brigham Young University Wai Y. Mok University of Alabama in Huntsville Sponsored](https://reader030.vdocuments.site/reader030/viewer/2022032704/56649d565503460f94a3514f/html5/thumbnails/6.jpg)
XNF → XML
GradStudent
FacultyMember
Hobby
Program
Department
GradStudent
FacultyMember
Hobby
Program
Department
F D
S P H
H
( F D ( S P ( H )* )* ( H )* )*
Kelly CS Pat PhD Hiking Hiking Skiing Skiing
Tracy MS Hiking Sailing
Chris MS
Lynn Math Sailing
![Page 7: Producing XML Documents with Guaranteed “Good” Properties David W. Embley Brigham Young University Wai Y. Mok University of Alabama in Huntsville Sponsored](https://reader030.vdocuments.site/reader030/viewer/2022032704/56649d565503460f94a3514f/html5/thumbnails/7.jpg)
Naive DTD Generation
F D
S P H
H
( F D ( S P ( H )* )* ( H )* )*
Kelly CS Pat PhD Hiking Hiking Skiing Skiing
Tracy MS Hiking Sailing
Chris MS
Lynn Math Sailing
<!DOCTYPE University[<!ELEMENT University ( ( Faculty_Member, Department, ( Grad_Student, Program, ( Hobby )* )* ( Hobby )* )*, <!ELEMENT Faculty_Member (#PCDATA)> …]>
![Page 8: Producing XML Documents with Guaranteed “Good” Properties David W. Embley Brigham Young University Wai Y. Mok University of Alabama in Huntsville Sponsored](https://reader030.vdocuments.site/reader030/viewer/2022032704/56649d565503460f94a3514f/html5/thumbnails/8.jpg)
Naive DTD Generation
F D
S P H
H
<!DOCTYPE University[<!ELEMENT University ( ( Faculty_Member, Department, ( Graduate_Student, Program, ( Hobby )* )* ( Hobby )* )*, <!ELEMENT Faculty_Member (#PCDATA)> …]> <University>
<Faculty_Member>Kelly</Faculty_Member> <Department>CS</Department> <Graduate_Student>Pat</Graduate_Student> <Program>PhD</Program> <Hobby_S>Hiking</Hobby_S> <Hobby_S>Skiing</Hobby_S> <Graduate_Student>Tracy</Graduate_Student> <Program>MS</Program> <Hobby_S>Hiking</Hobby_S> <Hobby_S>Sailing</Hobby_S> <Graduate_Student>Chris</Graduate_Student> <Program>MS</Program> <Hobby_F>Hiking</Hobby_F> <Hobby_F>Skiing</Hobby_F> <Faculty_Member>Lynn</Facutly_Member> <Hobby_F>Sailing</Hobby_F></University>
![Page 9: Producing XML Documents with Guaranteed “Good” Properties David W. Embley Brigham Young University Wai Y. Mok University of Alabama in Huntsville Sponsored](https://reader030.vdocuments.site/reader030/viewer/2022032704/56649d565503460f94a3514f/html5/thumbnails/9.jpg)
Sophisticated DTD Generation
F D
S P H
H
Faculty Members
Grad_Students
Hobbies
Hobbies
<!DOCTYPE University[<!ELEMENT University (Faculty_Members)> <!ELEMENT Faculty_Members (Faculty_Member)*> <!ELEMENT Faculty_Member (Department, Grad_Students, Hobbies)> <!ATTLIST Faculty_Member value CDATA #REQUIRED> <!ELEMENT Department (#PCDATA) <!ELEMENT Grad_Students (Grad_Student)*> <!ELEMENT Grad_Student (Program, Hobbies)> …]>
<University> <Faculty_Members> <Faculty_Member value=“Kelly”> <Department>CS</Department> <Grad_Students> <Grad_Student value=“Pat”> <Program>PhD</Program> <Hobbies> <Hobby>Hiking</Hobby> <Hobby>Skiing</Hobby> </Hobbies> </Grad_Student> <Grad_Student value=“Tracy”> … </Faculty_Members></University>
![Page 10: Producing XML Documents with Guaranteed “Good” Properties David W. Embley Brigham Young University Wai Y. Mok University of Alabama in Huntsville Sponsored](https://reader030.vdocuments.site/reader030/viewer/2022032704/56649d565503460f94a3514f/html5/thumbnails/10.jpg)
→ XNF
GradStudent
FacultyMember
Hobby
Program
Department
GradStudent
FacultyMember
Hobby
Program
Department
F D
S P H
H
( F D ( S P ( H )* )* ( H )* )*
Kelly CS Pat PhD Hiking Hiking Skiing Skiing
Tracy MS Hiking Sailing
Chris MS
Lynn Math Sailing
How do we generateXNF scheme-trees?
![Page 11: Producing XML Documents with Guaranteed “Good” Properties David W. Embley Brigham Young University Wai Y. Mok University of Alabama in Huntsville Sponsored](https://reader030.vdocuments.site/reader030/viewer/2022032704/56649d565503460f94a3514f/html5/thumbnails/11.jpg)
Alg. 1
GradStudent
FacultyMember
Hobby
Program
Department
GradStudent
FacultyMember
Hobby
Program
Department
F D
S P H
H
How do we generateXNF scheme-trees?
Algorithm 1Until all vertices and edges are included: Find a start vertex: -- included in most enclosures -- back off by one, if possible Grow a tree as large as possible: -- cut out hierarchy (watch out for optionals) -- add adjacent vertices: -- within node (for functional edges) -- below node (for non-functional edges)
![Page 12: Producing XML Documents with Guaranteed “Good” Properties David W. Embley Brigham Young University Wai Y. Mok University of Alabama in Huntsville Sponsored](https://reader030.vdocuments.site/reader030/viewer/2022032704/56649d565503460f94a3514f/html5/thumbnails/12.jpg)
Alg. 1: Start
GradStudent
FacultyMember
Hobby
Program
Department
GradStudent
FacultyMember
Hobby
Program
Department
F D
S P H
H
How do we generateXNF scheme-trees?
Algorithm 1Until all vertices and edges are included: Find a start vertex: -- included in most enclosures -- back off by one, if possible Grow a tree as large as possible: -- cut out hierarchy (watch out for optionals) -- add adjacent vertices: -- within node (for functional edges) -- below node (for non-functional edges)
1
2 3
1 2
![Page 13: Producing XML Documents with Guaranteed “Good” Properties David W. Embley Brigham Young University Wai Y. Mok University of Alabama in Huntsville Sponsored](https://reader030.vdocuments.site/reader030/viewer/2022032704/56649d565503460f94a3514f/html5/thumbnails/13.jpg)
Alg. 1: Start
GradStudent
FacultyMember
Hobby
Program
Department
GradStudent
FacultyMember
Hobby
Program
Department
F D
S P H
H
How do we generateXNF scheme-trees?
Algorithm 1Until all vertices and edges are included: Find a start vertix: -- included in most enclosures -- back off by one, if possible Grow a tree as large as possible: -- cut out hierarchy (watch out for optionals) -- add adjacent vertices: -- within node (for functional edges) -- below node (for non-functional edges)
1
2 3
1 2
![Page 14: Producing XML Documents with Guaranteed “Good” Properties David W. Embley Brigham Young University Wai Y. Mok University of Alabama in Huntsville Sponsored](https://reader030.vdocuments.site/reader030/viewer/2022032704/56649d565503460f94a3514f/html5/thumbnails/14.jpg)
GradStudent
FacultyMember
Hobby
Program
Department
GradStudent
FacultyMember
Hobby
Program
DepartmentAlg. 1: Grow
F D
S P H
H
How do we generateXNF scheme-trees?
Algorithm 1Until all vertices and edges are included: Find a start vertex: -- included in most enclosures -- back off by one, if possible Grow a tree as large as possible: -- cut out hierarchy (watch out for optionals) -- add adjacent vertices: -- within node (for functional edges) -- below node (for non-functional edges)
![Page 15: Producing XML Documents with Guaranteed “Good” Properties David W. Embley Brigham Young University Wai Y. Mok University of Alabama in Huntsville Sponsored](https://reader030.vdocuments.site/reader030/viewer/2022032704/56649d565503460f94a3514f/html5/thumbnails/15.jpg)
Alg. 1: Grow
GradStudent
FacultyMember
Hobby
Program
Department
GradStudent
FacultyMember
Hobby
Program
Department
F D
S P H
H
How do we generateXNF scheme-trees?
Algorithm 1Until all vertices and edges are included: Find a start vertex: -- included in most enclosures -- back off by one, if possible Grow a tree as large as possible: -- cut out hierarchy (watch out for optionals) -- add adjacent vertices: -- within node (for functional edges) -- below node (for non-functional edges)
√
![Page 16: Producing XML Documents with Guaranteed “Good” Properties David W. Embley Brigham Young University Wai Y. Mok University of Alabama in Huntsville Sponsored](https://reader030.vdocuments.site/reader030/viewer/2022032704/56649d565503460f94a3514f/html5/thumbnails/16.jpg)
Alg. 1: Grow
GradStudent
FacultyMember
Hobby
Program
Department
GradStudent
FacultyMember
Hobby
Program
Department
F D
S P H
H
How do we generateXNF scheme-trees?
Algorithm 1Until all vertices and edges are included: Find a start vertex: -- included in most enclosures -- back off by one, if possible Grow a tree as large as possible: -- cut out hierarchy (watch out for optionals) -- add adjacent vertices: -- within node (for functional edges) -- below node (for non-functional edges)
√
√
![Page 17: Producing XML Documents with Guaranteed “Good” Properties David W. Embley Brigham Young University Wai Y. Mok University of Alabama in Huntsville Sponsored](https://reader030.vdocuments.site/reader030/viewer/2022032704/56649d565503460f94a3514f/html5/thumbnails/17.jpg)
Algorithm 1 Yields XNF
Theorem. Given a canonical, binary conceptual-model (CM)hypergraph H, Algorithm 1 generates an XNF scheme-treeforest with respect to the FDs and MVDs of H.
Proof: Based on NNF (Mok, et al., TODS, 1996)
What is this restriction?
Can we relax this constraint?
Can we enlarge the set of dependencies?
![Page 18: Producing XML Documents with Guaranteed “Good” Properties David W. Embley Brigham Young University Wai Y. Mok University of Alabama in Huntsville Sponsored](https://reader030.vdocuments.site/reader030/viewer/2022032704/56649d565503460f94a3514f/html5/thumbnails/18.jpg)
Non-Canonical CM Hypergraphs
GradStudent
DepartmentFacultyMember
Hobby
ProgramGradStudent
DepartmentFacultyMember
Hobby
Program
If the input CM hypergraph has redundancy, Algorithm 1generates scheme trees with potential redundancy.
D
F S
S P H
H
The set of studentsmust be the samefor every department.
F D
S P D H
H
A faculty member’sdepartment is the sameas the faculty member’sstudents’ department.A CM hypergraph is canonical if:
(1) No edge is redundant,(2) No edge is losslessly decomposable, and(3) No vertex is redundant.
![Page 19: Producing XML Documents with Guaranteed “Good” Properties David W. Embley Brigham Young University Wai Y. Mok University of Alabama in Huntsville Sponsored](https://reader030.vdocuments.site/reader030/viewer/2022032704/56649d565503460f94a3514f/html5/thumbnails/19.jpg)
Non-Binary CM Hypergraphs
Address DayTime
Name Course
Phone
Major
Address DayTime
Name Course
Phone
Major
Address
Name Course
DayTimePhone
Major
Address
Name Course
DayTimePhone
Major
Not Canonical:Decomposable
![Page 20: Producing XML Documents with Guaranteed “Good” Properties David W. Embley Brigham Young University Wai Y. Mok University of Alabama in Huntsville Sponsored](https://reader030.vdocuments.site/reader030/viewer/2022032704/56649d565503460f94a3514f/html5/thumbnails/20.jpg)
Generating Scheme Trees fromNon-Binary CM Hypergraphs
Address
Name Course
DayTimePhone
Major
Address
Name Course
DayTimePhone
Major
N A M
C
C
D
T
C
D Tor or …
A P
![Page 21: Producing XML Documents with Guaranteed “Good” Properties David W. Embley Brigham Young University Wai Y. Mok University of Alabama in Huntsville Sponsored](https://reader030.vdocuments.site/reader030/viewer/2022032704/56649d565503460f94a3514f/html5/thumbnails/21.jpg)
Alg. 2
Address
Name Course
DayTimePhone
Major
Address
Name Course
DayTimePhone
Major
N A M
C
C
D
T
A P Algorithm 2Until all vertices and edges are included: Find a start edge and configure it Grow a tree as large as possible -- cut out hierarchy (watch out for optionals) -- add and configure edges
![Page 22: Producing XML Documents with Guaranteed “Good” Properties David W. Embley Brigham Young University Wai Y. Mok University of Alabama in Huntsville Sponsored](https://reader030.vdocuments.site/reader030/viewer/2022032704/56649d565503460f94a3514f/html5/thumbnails/22.jpg)
Alg. 2: Start
Address
Name Course
DayTimePhone
Major
Address
Name Course
DayTimePhone
Major
N A M
C
C
D
T
A P Algorithm 2Until all vertices and edges are included: Find a start edge and configure it Grow a tree as large as possible -- cut out hierarchy (watch out for optionals) -- add and configure edges
√
![Page 23: Producing XML Documents with Guaranteed “Good” Properties David W. Embley Brigham Young University Wai Y. Mok University of Alabama in Huntsville Sponsored](https://reader030.vdocuments.site/reader030/viewer/2022032704/56649d565503460f94a3514f/html5/thumbnails/23.jpg)
Alg. 2: Grow
Address
Name Course
DayTimePhone
Major
Address
Name Course
DayTimePhone
Major
N A M
C
C
D
T
A P Algorithm 2Until all vertices and edges are included: Find a start edge and configure it Grow a tree as large as possible -- cut out hierarchy (watch out for optionals) -- add and configure edges
![Page 24: Producing XML Documents with Guaranteed “Good” Properties David W. Embley Brigham Young University Wai Y. Mok University of Alabama in Huntsville Sponsored](https://reader030.vdocuments.site/reader030/viewer/2022032704/56649d565503460f94a3514f/html5/thumbnails/24.jpg)
Alg. 2: Start Again & Grow
Address
Name Course
DayTimePhone
Major
Address
Name Course
DayTimePhone
Major
N A M
C
C
D
T
A P Algorithm 2Until all vertices and edges are included: Find a start edge and configure it Grow a tree as large as possible -- cut out hierarchy (watch out for optionals) -- add and configure edges
√
![Page 25: Producing XML Documents with Guaranteed “Good” Properties David W. Embley Brigham Young University Wai Y. Mok University of Alabama in Huntsville Sponsored](https://reader030.vdocuments.site/reader030/viewer/2022032704/56649d565503460f94a3514f/html5/thumbnails/25.jpg)
Alg. 2: Start Again and Grow
Address
Name Course
DayTimePhone
Major
Address
Name Course
DayTimePhone
Major
N A M
C
C
D
T
A P Algorithm 2Until all vertices and edges are included: Find a start edge and configure it Grow a tree as large as possible -- cut out hierarchy (watch out for optionals) -- add and configure edges
√
![Page 26: Producing XML Documents with Guaranteed “Good” Properties David W. Embley Brigham Young University Wai Y. Mok University of Alabama in Huntsville Sponsored](https://reader030.vdocuments.site/reader030/viewer/2022032704/56649d565503460f94a3514f/html5/thumbnails/26.jpg)
Algorithm 2 Yields XNF
Theorem. Given a canonical conceptual-model (CM)hypergraph H, Algorithm 2 generates an XNF scheme-treeforest with respect to the FDs and MVDs of H.
Proof: Based on NNF (Mok, et al., TODS, 1996)
![Page 27: Producing XML Documents with Guaranteed “Good” Properties David W. Embley Brigham Young University Wai Y. Mok University of Alabama in Huntsville Sponsored](https://reader030.vdocuments.site/reader030/viewer/2022032704/56649d565503460f94a3514f/html5/thumbnails/27.jpg)
Inclusion Dependencies (IDs)
Hobby
FacultyMemberwith Hobby
GradStudentwith Hobby
FacultyMember
GradStudent
Advisor
Department
Program
Hobby
FacultyMemberwith Hobby
GradStudentwith Hobby
FacultyMember
GradStudent
Advisor
Department
Program
optionalconnections
![Page 28: Producing XML Documents with Guaranteed “Good” Properties David W. Embley Brigham Young University Wai Y. Mok University of Alabama in Huntsville Sponsored](https://reader030.vdocuments.site/reader030/viewer/2022032704/56649d565503460f94a3514f/html5/thumbnails/28.jpg)
Inclusion Dependencies (IDs)
Hobby
Grad-StudentHobbies
Faculty-MemberHobbies
GradStudentwith Hobby
FacultyMemberwith Hobby
FacultyMember
GradStudent
Advisor
Department
Program
Hobby
Grad-StudentHobbies
Faculty-MemberHobbies
GradStudentwith Hobby
FacultyMemberwith Hobby
FacultyMember
GradStudent
Advisor
Department
Program
This constraint makesthis vertex redundant.
![Page 29: Producing XML Documents with Guaranteed “Good” Properties David W. Embley Brigham Young University Wai Y. Mok University of Alabama in Huntsville Sponsored](https://reader030.vdocuments.site/reader030/viewer/2022032704/56649d565503460f94a3514f/html5/thumbnails/29.jpg)
Canonical CM Hypergraph with IDs
Grad-StudentHobbies
Faculty-MemberHobbies
GradStudentwith Hobby
FacultyMemberwith Hobby
FacultyMember
GradStudent
Advisor
Department
ProgramGrad-StudentHobbies
Faculty-MemberHobbies
GradStudentwith Hobby
FacultyMemberwith Hobby
FacultyMember
GradStudent
Advisor
Department
Program
![Page 30: Producing XML Documents with Guaranteed “Good” Properties David W. Embley Brigham Young University Wai Y. Mok University of Alabama in Huntsville Sponsored](https://reader030.vdocuments.site/reader030/viewer/2022032704/56649d565503460f94a3514f/html5/thumbnails/30.jpg)
Generating Scheme Trees fromCanonical CM Hypergraph with IDs
Grad-StudentHobbies
Faculty-MemberHobbies
GradStudentwith Hobby
FacultyMemberwith Hobby
FacultyMember
GradStudent
Advisor
Department
ProgramGrad-StudentHobbies
Faculty-MemberHobbies
GradStudentwith Hobby
FacultyMemberwith Hobby
FacultyMember
GradStudent
Advisor
Department
Program
F D
S P HF
HS
Algorithm 3Collapse G/S hierarchiesIf the edges are all binary Execute Algorithm 1Else Execute Algorithm 2
![Page 31: Producing XML Documents with Guaranteed “Good” Properties David W. Embley Brigham Young University Wai Y. Mok University of Alabama in Huntsville Sponsored](https://reader030.vdocuments.site/reader030/viewer/2022032704/56649d565503460f94a3514f/html5/thumbnails/31.jpg)
Alg. 3: Collapse
Grad-StudentHobbies
Faculty-MemberHobbies
GradStudentwith Hobby
FacultyMemberwith Hobby
FacultyMember
GradStudent
Advisor
Department
ProgramGrad-StudentHobbies
Faculty-MemberHobbies
GradStudentwith Hobby
FacultyMemberwith Hobby
FacultyMember
GradStudent
Advisor
Department
Program
F D
S P HF
HS
Algorithm 3Collapse G/S hierarchiesIf the edges are all binary Execute Algorithm 1Else Execute Algorithm 2
![Page 32: Producing XML Documents with Guaranteed “Good” Properties David W. Embley Brigham Young University Wai Y. Mok University of Alabama in Huntsville Sponsored](https://reader030.vdocuments.site/reader030/viewer/2022032704/56649d565503460f94a3514f/html5/thumbnails/32.jpg)
Alg. 3: Collapse
F D
S P HF
HS
Algorithm 3Collapse G/S hierarchiesIf the edges are all binary Execute Algorithm 1Else Execute Algorithm 2
GradStudent
Grad-StudentHobbies
FacultyMember
Faculty-MemberHobbies
Department
ProgramGradStudent
Grad-StudentHobbies
FacultyMember
Faculty-MemberHobbies
Department
Program
![Page 33: Producing XML Documents with Guaranteed “Good” Properties David W. Embley Brigham Young University Wai Y. Mok University of Alabama in Huntsville Sponsored](https://reader030.vdocuments.site/reader030/viewer/2022032704/56649d565503460f94a3514f/html5/thumbnails/33.jpg)
Alg. 3: Execute
F D
S P HF
HS
Algorithm 3Collapse G/S hierarchiesIf the edges are all binary Execute Algorithm 1Else Execute Algorithm 2
GradStudent
Grad-StudentHobbies
FacultyMember
Faculty-MemberHobbies
Department
ProgramGradStudent
Grad-StudentHobbies
FacultyMember
Faculty-MemberHobbies
Department
Program
![Page 34: Producing XML Documents with Guaranteed “Good” Properties David W. Embley Brigham Young University Wai Y. Mok University of Alabama in Huntsville Sponsored](https://reader030.vdocuments.site/reader030/viewer/2022032704/56649d565503460f94a3514f/html5/thumbnails/34.jpg)
Algorithm 3 Yields XNF
Theorem. Given a canonical conceptual-model (CM)hypergraph H, Algorithm 3 generates an XNF scheme-treeforest with respect to the FDs, MVDs, and IDs of H.
Proof: Based on NNF (Mok, et al., TODS, 1996)
![Page 35: Producing XML Documents with Guaranteed “Good” Properties David W. Embley Brigham Young University Wai Y. Mok University of Alabama in Huntsville Sponsored](https://reader030.vdocuments.site/reader030/viewer/2022032704/56649d565503460f94a3514f/html5/thumbnails/35.jpg)
Conclusions
XNF ~ “Good” XML No redundancy As few trees as possible
Elegant DTD generation Algorithms to generate XNF Proofs of correctness
[email protected]@email.uah.edu