154 research outputs found
Programming Languages for Big Data (PlanBig) (Dagstuhl Seminar 14511)
No full textThis report documents the program and the outcomes of Dagstuhl
Seminar 14511 "Programming Languages for Big Data (PlanBig)". The
seminar was motivated by recent developments in programming
languages, databases, machine learning, and cloud computing, and
particularly by the opportunities offered by research drawing on
more than one of these areas. Participants included researchers
working in each of these areas and several who have previously been
involved in research in the intersection of databases and
programming languages. The seminar included talks, demos and free
time for discussion or collaboration. This report collects the
abstracts of talks and other activities, a summary of the group
discussions at the seminar, and a list of outcomes
06472 Executive Summary – XQuery Implementation Paradigms
No full textOnly a couple of weeks after the participants of seminar No. 06472 met
in Dagstuhl, the W3C published the Final Recommendation documents that
fix the XQuery 1.0 syntax, data model, formal semantics, built-in
function library and the interaction with the XML Schema Recommendations
(see W3C's XQuery web site at http://www.w3.org/XML/Query/). With
the language's standardization nearing its end and now finally in place,
the many efforts to construct correct, complete, and efficient
implementations of XQuery finally got rid of the hindering "moving
target'' syndrome. This Dagstuhl seminar on the different XQuery
implementation paradigms that have emerged in the recent past, thus was
as timely as it could have possibly been
06472 Abstracts Collection - XQuery Implementation Paradigms
No full textFrom 19.11.2006 to 22.11.2006, the Dagstuhl Seminar 06472 ``XQuery Implementation Paradigms'' was held in the International Conference and Research Center (IBFI), Schloss Dagstuhl. During the seminar, several participants presented their current research, and ongoing work and open problems were discussed. Abstracts of the presentations given during the seminar as well as abstracts of seminar results and ideas are put together in this paper. The first section describes the seminar topics and goals in general. Links to extended abstracts or full papers are provided, if available
06472 Abstracts Collection – XQuery Implementation Paradigms
No full textFrom 19.11.2006 to 22.11.2006, the Dagstuhl Seminar 06472 ``XQuery Implementation Paradigms'' was held in the International Conference and Research Center (IBFI),
Schloss Dagstuhl.
During the seminar, several participants presented their current
research, and ongoing work and open problems were discussed. Abstracts of
the presentations given during the seminar as well as abstracts of
seminar results and ideas are put together in this paper. The first section
describes the seminar topics and goals in general.
Links to extended abstracts or full papers are provided, if available
06472 Executive Summary - XQuery Implementation Paradigms
No full textOnly a couple of weeks after the participants of seminar No. 06472 met in Dagstuhl, the W3C published the Final Recommendation documents that fix the XQuery 1.0 syntax, data model, formal semantics, built-in function library and the interaction with the XML Schema Recommendations (see W3C's XQuery web site at http://www.w3.org/XML/Query/). With the language's standardization nearing its end and now finally in place, the many efforts to construct correct, complete, and efficient implementations of XQuery finally got rid of the hindering "moving target'' syndrome. This Dagstuhl seminar on the different XQuery implementation paradigms that have emerged in the recent past, thus was as timely as it could have possibly been
Accelerating XPath Location Steps
No full textThis work is a proposal for a database index structure that has been specifically designed to support the evaluation of XPath queries. As such, the index is capable to support all XPath axes (including ancestor, following, preceding-sibling, descendant-or-self, etc.). This feature lets the index stand out among related work on XML indexing structures which had a focus on regular path expressions (which correspond to the XPath axes children and descendant-or-self plus name tests). Its ability to start traversals from arbitrary context nodes in an XML document additionally enables the index to support the evaluation of path traversals embedded in XQuery expressions. Despite its flexibility, the new index can be implemented and queried using purely relational techniques, but it performs especially well if the underlying database host provides support for R-trees. A performance assessment which shows quite promising results completes this proposal
The Construction of an SASL-Compiler
No full textthis article describes all techniques needed to compile and execute SASL programs. In this article, Turner established a technique calle
Comprehending queries
No full textThis text describes a world in which datatypes determine thecomprehension of database queries. In this world, a datatype ischaracterized by its algebra of value constructors. These algebrasare principal. Query operators are secondary in the sense that theysimply box (recursive) programs that describe how to form a queryresult by application of datatype constructors. Often, operators willbe unboxed to inspect and possibly rewrite these programs. Queryoptimization then means to deal with the transformation of programs.The predominant role of the constructor algebras suggests that thismodel understands queries as mappings between such algebras. The keyobservation that makes the whole approach viable is that (a)homomorphic mappings are expressive enough to cover declarativequery languages like OQL or SQL dialects, and, at the same time, (b) asingle program form suffices to express homomorphisms betweenconstructor algebras.Reliance on a single combining form, catamorphisms, renders the queryprograms susceptible to Constructive Algorithmics, an effective andextensive algebraic theory of program transformations.The text then takes a step towards a higher-level query representationbased on the categorical notion of monads, the monad comprehensioncalculus. Built on top of the monad notion, the calculus maps avariety of query constructs to few syntactic forms. The uniformity ofthe calculus facilitates the analysis and transformation, especiallythe normalization, of its expressions. Few but generic calculusrewriting rules suffice to implement query transformations that wouldotherwise require extensive rule sets.The text rediscovers well-known query optimization knowledge onsometimes unusual paths that are more practicable to follow for anoptimizer, though. Solutions previously proposed by others can besimplified and generalized mainly due to the clear account of thestructure of queries that the monadpublishe
Tree Awareness for Relational DBMS Kernels: Staircase Join
No full textRelational database management systems (RDBMSs) derive much of their eciency from the versatility of their core data structure: tables of tuples. Such tables are simple enough to allow for an ecient representation on all levels of the memory hierarchy, yet suciently generic to host a wide rang
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