|
To find data in XML documents, we can use query technologies that
exploit the document's structure. XPath enables us to use expressions to
traverse a document tree. XQuery enables us to stipulate search criteria
for finding data in an XML document. RDF enables us to provide semantic information.
Featured Links
List of XQuery
Processors and Engines
An Efficient SQL-based RDF Querying Scheme
Eugene Inseok Chong, Souripriya Das, George Eadon, Jagannathan Srinivasan (Oracle)
The authors take advantage of the extensibility of SQL platforms by introducing the RDF_MATCH function for queries over RDF triples.
This approach provides the benefit of using RDF in combination with SQL's querying capabilities, including query optimization. The first
argument to RDF_MATCH uses SPARQL-like syntax.
A TeXQuery-Based XML Full-Text Search Engine
Chavdar Botev, Jayavel Shanmugasundaram (Cornell University), Sihem
Amer-Yahia (AT&T Labs–Research)
The authors note the full-text searching limitations of XQuery 1.0. They
propose the TeXQuery language as a full-text searching extension to
XQuery. TeXQuery provides full-text primitives such as phrase matching,
proximity distance, stemming and thesauri.
Efficient XML-to-SQL Query Translation: Where to Add the Intelligence?
Rajasekar Krishnamurthy (IBM Almaden Research
Center),
Raghav Kaushik
(Microsoft Research), Jeffrey F. Naughton (university of
Wisconsin-Madison)
The authors present a translation
algorithm for generating efficient SQL for path expressions over tree
schemas.
Projecting XML Documents
Amélie Marian (Columbia University), Jérôme Siméon (Bell Laboratories)
The authors note that small documents break memory-based XQuery
processors. They also discuss the problem of processing large documents
(7 MB - 145 MB) with several XQuery and XSLT
processors. The authors discuss XML projection and introduce a static analysis algorithm
for XQuery. They also introduce a loading algorithm that builds a
projected document from a set of paths.
Rainbow:
MultiXQuery Optimization Using Materialized XML Views
Xin Zhang, Katica Dimitrova, Ling Wang, Maged El Sayed, Brian Murphy,
Bradford
Pielech, Mukesh Mulchandani, Luping Ding, Elke A. Rundensteiner
(Worcester Polytechnic Institute)
The authors discuss the process of XQuery optimization based on
materialized views and rewriting queries. They also use an XAT algebra
tree to generate a single access plan for multiple queries.
XQuery on SQL Hosts
Torsten Grust, Sherif Sakr, Jens Teubner (University
of Konstanz)
The authors take a purely relational approach to
XQuery by compiling XQuery expressions into SQL code that operates on
trees. The authors suggest SQL OLAP ranking and partitioning
functionality is a good match for XQuery.
XQuery Optimization
Philippe Michiels (University of Antwerp, Belgium)
The author discusses the XPath approach to optimizing queries and a
pipelined approach using parameterized algebraic expressions. The author
also discusses duplicate elimination, an approach using core mapping,
and a solution using schemas to compute path equivalence classes.
A Data Model and Algebra for XML Query
Mary F. Fernández AT&T Labs, Jérôme Siméon (Bell Labs), Dan Suciu (AT&T Labs), Philip Wadler (Bell Labs)
This paper presents a data model and algebra derived from the nested
relational algebra, which is widely-used for semi-structured and object-oriented databases.
A Comprehensive XQuery to SQL Translation using Dynamic Interval Encoding
David DeHaan, David Toman, Mariano P. Consens, M. Tamer Özsu (University of
Waterloo)
This paper describes a dynamic interval encoding of XML documents as relations. XQuery expressions map to a single equivalent SQL query and the result is predictable query plans that do not restrict the use of sort-merge join query operators. The authors' approach is based on representing a document as an XML forest (an ordered forest of rooted, node-labeled ordered trees).
Active XQuery
Angela Bonifati, Daniele Braga, Alessandro Campi, Stefano Ceri (Politecnico
di Milano)
This paper proposes extensions to XQuery to provide triggers similar
to SQL:99 BEFORE and AFTER triggers. The authors' work is based on a
proposed XQuery extension for updates. The authors developed an
algorithm for executing bulk updates as a collection of equivalent
statements, each a self-standing XQuery updates.
A Formal Data Model and Algebra for XML
Dr. Ashok Malhotra, Dr. Michael Rys (Microsoft), David Beech (Oracle)
This paper presents a formal XML data model and describes the algebra for queries over XML data (operations on the data model).
It's a precursor to XML Query Working Group development of a formal
query data model.
An
Introduction to XQuery
This is an excellent introduction to XQuery by Howard Katz, the author
of XQEngine (Java-based XQuery engine).
The
BEA/XQRL Streaming XQuery Processor
Daniela Florescu, Chris Hillery, Donald Kossmann, Paul Lucas, Fabio
Riccardi, Till Westmann, Michael J. Carey, Arvind Sundararajan (BEA
Systems), Geetika Agrawal (Stanford University)
This paper describes the design of an XQuery processor intended to
deliver performance in message processing applications while
implementing the full XQuery language. The authors discuss three
managers used in the process of compiling and optimizing queries.
Galax
XQuery Optimization
This page provides detail of the Galax query optimization process. It
explains pre-processing, algebraic optimization, and XML projection.
Implementing the
XQuery Grammar
Howard Katz (Fatdog Software)
This was a presentation at the Extreme Markup 2002 conference. Howard
discusses using Java tools (JavaCC, JJTree) to implement an XQuery
engine. JJTree is a preprocessor and JavaCC is parser generator.
The Lorel Query Language for Semistructured Data
Serge Abiteboul, Dallan Quass, Jason McHugh, Jennifer Widom, Janet L. Wiener
(Stanford University)
Lorel is a loosely-type language for querying semi-structured data. The underlying data model is the Object Exchange Model with self-describing, nested objects and atomic objects as vertices. The database can be represented as a graph and queries find paths in a graph.
Observations on Structured Document Query Languages
Makoto Murata, Jonathan Robie
This was one of the foundation documents for the eventual development of Quilt and the XML Query language (XQuery).
OJXQI The Oracle Java XQuery API
This document explains an Oracle API for Java developers running XQuery queries.
OJXQI is a JDBC-like API. You compile XQuery statements, bind to values, and process result sets
(XQueryResultSet).
Preserving and Querying Histories of
XML-Published Relational Databases
Fusheng Wang, Carlo Zaniolo (University of California, Los Angeles)
The authors discuss how to use XML views to present database
information. The authors discuss the issue of preserving XML histories
and how to formulate XQuery temporal queries that are not easily
expressible as SQL.
Querying
Semi-structured Data Based on Schema Matching
Andre Bergholz, J.C. Freytag
This paper explains how to use queries to derive partial schemata for
semi-structured data.
Querying
XML Documents
John A. Miller, Sonali Sheth
IEEE Potentials article presents an overview of query.
Quilt
This XML query language was the foundation for XQuery. Quilt was the
work of Don Chamberlin, Daniela Florescu and Jonathan Robie.
Searching
in Context with XML
Daniel Egnor, Robert Lord
This paper was presented at the ACM SIGIR 2000 Workshop on XML and Information Retrieval.
It describes using context and
structure to search XML documents.
Topic Map Query Language
The topic map community feels neither SQL nor XQuery is ideally suited
for querying topic maps. This solution is a new query language called TMQL.
UXQuery: Building Updatable XML Views over Relational Databases
Vanessa P. Braganholo1, Carl Heuser (Universidade Federal do Rio Grande
do Sul), Susan B. Davidson (University of Pennsylvania)
This paper explains how to use a subset of XQuery to build updatable
XML views. The authors also show how to map the
XQuery views to a set of relational views for the purposes of updating
relational tables.
XML
Query Algebra
The W3C working group that created XQuery defined a formal data
model and query algebra. Query processors use the data model and the operations (or algebra)
defined for that data model. A formal algebra makes it possible to
perform type checking and optimize queries.
XML Query Data Model
This document from the XQuery working group explains the query data
model based on XML Information Set. It describes the XML
Query Algebra.
XML Query Forms
Michalis Petropoulos, Yannis Papakonstantinou (UCSD), Vasilis Vassalos (NYU)
XQForms is a visual query tool that uses XML schemas. It uses a compiler to translate form declarations and works with XSL scripts to format reports.
XML
Query Requirements
The XQuery working group describes query
requirements: data model, query operators, and the query
language.
XML
Query (WWW9)
Mary Fernandez, Massimo Marchiori
This is a WWW9 presentation about the W3C XML Query effort.
XPath
The XPath language defines expressions and
functions for navigating into documents. XPath 1.0 is a
Recommendation. XPath 2.0 is currently
a working draft.
XML Path Language (XPath 2.0)
XPath 2.0 is an expression language for processing values that conform
to the XQuery and XPath 2.0 data model (a tree representation of XML
documents). The result of an XPath expression can be a node list, an
atomic value, or a sequence.
XQBE: A Graphical Interface for XQuery Engines
Daniele Braga, Alessandro Campi, Stefano Ceri (Politecnico di Milano)
XQBE is an XQuery tool that uses hierarchical structures to visually
represent input and output documents. XQBE normalizes and parses a query
and then builds a graph.
XQuery 1.0 (Working Draft)
XQuery has reached the last call working draft stage. It was defined jointly by the XML Query Working Group and the XSL Working Group.
XQuery 1.0 and XPath 2.0 Formal Semantics
XQuery/XPath is a functional language built from expressions. This
document explains the dynamic and static semantics of XQuery/XPath
expressions. This is a W3C working draft from the XML Query and XSL working groups.
XQuery
1.0 and XPath 2.0 Functions and Operators
This W3C document specifies functions and operators used with XML
Schema, XPath, and XQuery types.
XQuery
and SQL: Vive la Différence
This article discusses XQuery, SQL and the XQuery API for Java (XQJ).
 Cyrillic
translation
|
