Results 21 to 30 of about 337,613 (156)
Proceedings of the VLDB Endowment, 2015 Driven by the dominance of the relational model, the requirements of modern applications, and the veracity of data, we revisit the fundamental notion of a key in relational databases with NULLs. In SQL database systems primary key columns are NOT NULL by
Henning Köhler, S. Link, Xiaofang Zhou
semanticscholar +1 more source
Rumble: Data Independence for Large Messy Data Sets
, 2020 This paper introduces Rumble, an engine that executes JSONiq queries on large, heterogeneous and nested collections of JSON objects, leveraging the parallel capabilities of Spark so as to provide a high degree of data independence. The design is based on
Alonso, Gustavo +4 more
core +1 more source
arXiv, 2023 Since the inception of SQL, nulls have frustrated database users and builders alike. Those writing SQL must painstakingly guard their queries against surprising results caused by nulls, while those building database engines constantly struggle to implement the subtle semantics of 3-valued logic. Given that the relational model already provides a way to
arxiv
Angewandte Chemie, Volume 137, Issue 6, February 3, 2025.Mixed matrix membranes containing two polymorphous cage networks (ZrT‐2α and ZrT‐2β) were fabricated using a packing engineering approach. Synchrotron X‐ray absorption and positron annihilation lifetime spectroscopy were employed to differentiate distinct polymorphic structures within the membrane matrix.
Ziqi Yang +5 more
wiley +2 more sources
A query description model based on basic semantic unit composite Petri-Net for soccer video [PDF]
, 2004 Digital video networks are making available increasing amounts of sports video data. The volume of material on offer means that sports fans often rely on prepared summaries of game highlights to follow the progress of their favourite teams. A significant
Jones, Gareth J.F. +3 more
core +1 more source
Querying Incomplete Numerical Data: Between Certain and Possible Answers [PDF]
arXiv, 2022 Queries with aggregation and arithmetic operations, as well as incomplete data, are common in real-world database, but we lack a good understanding of how they should interact. On the one hand, systems based on SQL provide ad-hoc rules for numerical nulls, on the other, theoretical research largely concentrates on the standard notions of certain and ...
arxiv
EasyChair Preprints, 2018 In this article, we provide a Coq mechanised, executable, formal semantics for realistic SQL queries consisting of select [distinct] from where group by having queries with NULL values, functions, aggregates, quantifiers and nested, potentially ...
Véronique Benzaken, Évelyne Contejean
semanticscholar +1 more source
CREOLE: a Universal Language for Creating, Requesting, Updating and Deleting Resources [PDF]
, 2010 In the context of Service-Oriented Computing, applications can be developed following the REST (Representation State Transfer) architectural style. This style corresponds to a resource-oriented model, where resources are manipulated via CRUD (Create ...
Grall, Hervé +2 more
core +6 more sources
Becoming NULL: Queer relations in the excluded middle
, 2018 This article investigates how computational media have come to shape the form and function of identity in contemporary society, suggesting that these technologies have conscripted users into systems of compulsory identification with or as a set of ...
J. Gaboury
semanticscholar +1 more source
ChemPlusChem, EarlyView.Two new [n]polynorbornane based ligands (LMe and LEt) form isoreticular sql MOFs with crystal structure analysis revealing neatly aligned nets creating large accessible 1D channels with a distinct lack of interpenetration. The ester moieties of these ligands orient into the channels highlighting potential of these ligands for the construction of MOFs ...
William Murrell +3 more
wiley +1 more source