Results 1 - 10
of
43
XDuce: A Statically Typed XML Processing Language
, 2002
"... this paper we describe a statically typed XML processing language called XDuce (o#cially pronounced "transduce"). XDuce is a functional language whose primitive data structures represent XML documents and whose types---called regular expression types---correspond to document schemas. The m ..."
Abstract
-
Cited by 174 (7 self)
- Add to MetaCart
this paper we describe a statically typed XML processing language called XDuce (o#cially pronounced "transduce"). XDuce is a functional language whose primitive data structures represent XML documents and whose types---called regular expression types---correspond to document schemas. The motivating principle behind its design is that a simple, clean, and powerful type system for XML processing can be based directly on the theory of regular tree automata
Integrity Constraints for XML
, 1999
"... this paper, we extend XML DTDs with several classes of integrity constraints and investigate the complexity of reasoning about these constraints. The constraints range over keys, foreign keys, inverse constraints as well as ID constraints for capturing the semantics of object identities. They imp ..."
Abstract
-
Cited by 97 (11 self)
- Add to MetaCart
this paper, we extend XML DTDs with several classes of integrity constraints and investigate the complexity of reasoning about these constraints. The constraints range over keys, foreign keys, inverse constraints as well as ID constraints for capturing the semantics of object identities. They improve semantic specifications and provide a better reference mechanism for native XML applications. They are also useful in information exchange and data integration for preserving the semantics of data originating in relational and object-oriented databases. We establish complexity and axiomatization results for the (finite) implication problems associated with these constraints. In addition, we study implication of more general constraints, such as functional, inclusion and inverse constraints defined in terms of navigation paths
XQuery on SQL Hosts
- In VLDB Conf
, 2004
"... Relational database systems may be turned into efficient XML and XPath processors if the system is provided with a suitable relational tree encoding. This paper extends this relational XML processing stack and shows that an RDBMS can also serve as a highly efficient XQuery runtime environment. Our a ..."
Abstract
-
Cited by 81 (31 self)
- Add to MetaCart
(Show Context)
Relational database systems may be turned into efficient XML and XPath processors if the system is provided with a suitable relational tree encoding. This paper extends this relational XML processing stack and shows that an RDBMS can also serve as a highly efficient XQuery runtime environment. Our approach is purely relational: XQuery expressions are compiled into SQL code which operates on the tree encoding. The core of the compilation procedure trades XQuery’s notions of variable scopes and nested iteration (FLWOR blocks) for equi-joins. The resulting relational XQuery processor closely adheres to the language semantics, e.g., it respects node identity as well as document and sequence order, and can support XQuery’s full axis feature. The system exhibits quite promising performance figures in experiments. Somewhat unexpectedly, we will also see that the XQuery compiler can make good use of SQL’s OLAP functionality. 1
Regular Object Types
- In European Conference on Object-Oriented Programming (ECOOP
, 2003
"... Regular expression types have been proposed as a foundation for statically typed processing of XML and similar forms of tree-structured data. To date, however, regular expression types have been explored in special-purpose languages (e.g., XDuce, CDuce, and XQuery) with type systems designed around ..."
Abstract
-
Cited by 68 (8 self)
- Add to MetaCart
(Show Context)
Regular expression types have been proposed as a foundation for statically typed processing of XML and similar forms of tree-structured data. To date, however, regular expression types have been explored in special-purpose languages (e.g., XDuce, CDuce, and XQuery) with type systems designed around regular expression types "from the ground up." The goal of the Xtatic language is to bring regular expression types to a broad audience by offering them as a lightweight extension of a popular object-oriented language, C#. We develop...
Schema-based Scheduling of Event Processors and Buffer Minimization for Queries on Structured Data Streams
- In Proc. VLDB 2004
, 2004
"... We introduce an extension of the XQuery language, FluX, that supports event-based query processing and the conscious handling of main memory buffers. Purely event-based queries of this language can be executed on streaming XML data in a very direct way. We then develop an algorithm that allows to ef ..."
Abstract
-
Cited by 57 (10 self)
- Add to MetaCart
We introduce an extension of the XQuery language, FluX, that supports event-based query processing and the conscious handling of main memory buffers. Purely event-based queries of this language can be executed on streaming XML data in a very direct way. We then develop an algorithm that allows to efficiently rewrite XQueries into the event-based FluX language. This algorithm uses order constraints from a DTD to schedule event handlers and to thus minimize the amount of buffering required for evaluating a query. We discuss the various technical aspects of query optimization and query evaluation within our framework. This is complemented with an experimental evaluation of our approach.
A Unified Constraint Model for XML
, 2002
"... Integrity constraints are an essential part of modern schema definition languages. They are useful for semantic specification, update consistency control, query optimization, etc. In this paper, we propose UCM, a model of integrity constraints for XML that is both simple and expressive. Because it r ..."
Abstract
-
Cited by 26 (1 self)
- Add to MetaCart
Integrity constraints are an essential part of modern schema definition languages. They are useful for semantic specification, update consistency control, query optimization, etc. In this paper, we propose UCM, a model of integrity constraints for XML that is both simple and expressive. Because it relies on a single notion of keys and foreign keys, the UCM model is easy to use and makes formal reasoning possible. Because it relies on a powerful type system, the UCM model is expressive, capturing in a single framework the constraints found in relational databases, object-oriented schemas and XML DTDs. We study the problem of consistency of UCM constraints, the interaction between constraints and subtyping, and algorithms for implementing these constraints.
Relational Algebra: Mother Tongue—XQuery: Fluent
- In Proc. of the 1st Twente Data Management Workshop (TDM
, 2004
"... This work may be seen as a further proof of the versatility of the relational database model. Here, we add XQuery to the catalog of languages which RDBMSs are able to \speak" °uently. Given suitable relational encodings of sequences and or-dered, unranked trees|the two data structures that form ..."
Abstract
-
Cited by 17 (8 self)
- Add to MetaCart
(Show Context)
This work may be seen as a further proof of the versatility of the relational database model. Here, we add XQuery to the catalog of languages which RDBMSs are able to \speak" °uently. Given suitable relational encodings of sequences and or-dered, unranked trees|the two data structures that form the backbone of the XML and XQuery data models|we de-scribe a compiler that translates XQuery expressions into a simple and quite standard relational algebra which we ex-pect to be e±ciently implementable on top of any relational query engine. The compilation procedure is fully composi-tional and emits algebraic code that strictly adheres to the XQuery language semantics: document and sequence order as well as node identity are obeyed. We exercise special care in translating arbitrarily nested XQuery FLWOR iteration constructs into equi-joins, an operation which RDBMSs can perform particularly fast. The resulting purely relational XQuery processor shows promising performance ¯gures in experiments.
Confessions of a used programming language salesman (getting the masses hooked on haskell
, 2006
"... When considering the past or the future, dear apprentice, be mindful of the present. If, while considering the past, you become caught in the past, lost in the past, or enslaved by the past, then you have forgotten yourself in the present. If, while considering the future, you become caught in the f ..."
Abstract
-
Cited by 16 (0 self)
- Add to MetaCart
(Show Context)
When considering the past or the future, dear apprentice, be mindful of the present. If, while considering the past, you become caught in the past, lost in the past, or enslaved by the past, then you have forgotten yourself in the present. If, while considering the future, you become caught in the future, lost in the future, or enslaved by the future, then you have forgotten yourself in the present. Conversely, when considering the past, if you do not become caught, lost, or enslaved by the past, then you have remained mindful of the present. And if, when considering the future, you do not become caught, lost, or enslaved in the future, then you have remained mindful of the present. [14] Programmers in the real world wrestle everyday to overcome the impedance mismatch between relational data, objects, and XML. We have been working on solving this problem for the past ten years by applying principles from functional programming, in particular monads and comprehensions. By viewing data as monads and formulating queries as comprehensions, it becomes possible to unify the three data models and their corresponding programming languages instead of considering each as a separate special case. To actually bring this within the reach of mainstream programmers we have worked tirelessly on transferring functional programming technology from pure Haskell, via Cω to the upcoming versions of C ♯ 3.0 and Visual Basic 9 and the LINQ framework. Functional programming has finally reached the masses, except that it is called Visual Basic instead of Lisp,
Workflow Mediation Using VorteXML
- IEEE Data Engineering Bulletin
, 2001
"... This paper presents an original framework for specifying, enacting and supervising e-services on the Web. This framework is based on XML and rules-based support for products/services description and workflow mediation across organizations ..."
Abstract
-
Cited by 10 (2 self)
- Add to MetaCart
(Show Context)
This paper presents an original framework for specifying, enacting and supervising e-services on the Web. This framework is based on XML and rules-based support for products/services description and workflow mediation across organizations
ROSA: a data model and query language for e-learning objects
- PGLDB Conference, PUC, Rio de Janeiro
, 2003
"... Learning Content Management Systems (LCMS) supports e-learning applications with storage and efficient access for e-learning objects (LO)s. ROSA is a LCMS built as a semantic layer on the top of an XML native DBMS, Tamino. Together, ROSA and Tamino, offer instructional designers a semantic view of e ..."
Abstract
-
Cited by 7 (2 self)
- Add to MetaCart
Learning Content Management Systems (LCMS) supports e-learning applications with storage and efficient access for e-learning objects (LO)s. ROSA is a LCMS built as a semantic layer on the top of an XML native DBMS, Tamino. Together, ROSA and Tamino, offer instructional designers a semantic view of e-learning content. In this paper, we present ROSA Data Model and Query Language, designed as an extension to RDF data model and RQL query language. The Data Model is structured around the LO modeling and their relationships, adapted to the e-learning domain. An algebra defines valid operations over LO data. Queries are formulated in ROSAQL that extends RQL with joins, graph navigation and recursion. 1.
