Database Systems (TODS)


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ACM Transactions on Database Systems (TODS), Volume 37 Issue 3, August 2012

Z. Meral Özsoyoǧlu
Article No.: 16
DOI: 10.1145/2338626.2338627

Foster b-trees
Goetz Graefe, Hideaki Kimura, Harumi Kuno
Article No.: 17
DOI: 10.1145/2338626.2338630

Foster B-trees are a new variant of B-trees that combines advantages of prior B-tree variants optimized for many-core processors and modern memory hierarchies with flash storage and nonvolatile memory. Specific goals include: (i) minimal...

Revisiting answering tree pattern queries using views
Junhu Wang, Jeffrey Xu Yu
Article No.: 18
DOI: 10.1145/2338626.2338631

We revisit the problem of answering tree pattern queries using views. We first show that, for queries and views that do not have nodes labeled with the wildcard *, there is an approach which does not require us to find any rewritings explicitly,...

Efficient reasoning about data trees via integer linear programming
Claire David, Leonid Libkin, Tony Tan
Article No.: 19
DOI: 10.1145/2338626.2338632

Data trees provide a standard abstraction of XML documents with data values: they are trees whose nodes, in addition to the usual labels, can carry labels from an infinite alphabet (data). Therefore, one is interested in decidable formalisms for...

Reordering rows for better compression: Beyond the lexicographic order
Daniel Lemire, Owen Kaser, Eduardo Gutarra
Article No.: 20
DOI: 10.1145/2338626.2338633

Sorting database tables before compressing them improves the compression rate. Can we do better than the lexicographical order? For minimizing the number of runs in a run-length encoding compression scheme, the best approaches to...

Entangled queries: Enabling declarative data-driven coordination
Nitin Gupta, Lucja Kot, Sudip Roy, Gabriel Bender, Johannes Gehrke, Christoph Koch
Article No.: 21
DOI: 10.1145/2338626.2338629

Many data-driven social and Web applications involve collaboration and coordination. The vision of Declarative Data-Driven Coordination (D3C), proposed in Kot et al. [2010], is to support coordination in the spirit of data management: to...

Artifact systems with data dependencies and arithmetic
Elio Damaggio, Alin Deutsch, Victor Vianu
Article No.: 22
DOI: 10.1145/2338626.2338628

We study the static verification problem for data-centric business processes, specified in a variant of IBM's “business artifact” model. Artifacts are records of variables that correspond to business-relevant objects and are updated by...