Serialization

Abstract: xarray is an open source project and Python package that provides a toolkit and data structures for N-dimensional labeled arrays. Our approach combines an application programing interface (API) inspired by pandas with the Common Data Model for self-described scientific data. Key features of the xarray package include label-based indexing and arithmetic, interoperability with the core scientific Python packages (e.g., pandas, NumPy, Matplotlib), out-of-core computation on datasets that don’t fit into memory, a wide range of serialization and input/output (I/O) options, and advanced multi-dimensional data manipulation tools such as group-by and resampling. xarray, as a data model and analytics toolkit, has been widely adopted in the geoscience community but is also used more broadly for multi-dimensional data analysis in physics, machine learning and finance.

Abstract: Snapshot Isolation (SI) is a multiversion concurrency control algorithm, first described in Berenson et al. [1995]. SI is attractive because it provides an isolation level that avoids many of the common concurrency anomalies, and has been implemented by Oracle and Microsoft SQL Server (with certain minor variations). SI does not guarantee serializability in all cases, but the TPC-C benchmark application [TPC-C], for example, executes under SI without serialization anomalies. All major database system products are delivered with default nonserializable isolation levels, often ones that encounter serialization anomalies more commonly than SI, and we suspect that numerous isolation errors occur each day at many large sites because of this, leading to corrupt data sometimes noted in data warehouse applications. The classical justification for lower isolation levels is that applications can be run under such levels to improve efficiency when they can be shown not to result in serious errors, but little or no guidance has been offered to application programmers and DBAs by vendors as to how to avoid such errors. This article develops a theory that characterizes when nonserializable executions of applications can occur under SI. Near the end of the article, we apply this theory to demonstrate that the TPC-C benchmark application has no serialization anomalies under SI, and then discuss how this demonstration can be generalized to other applications. We also present a discussion on how to modify the program logic of applications that are nonserializable under SI so that serializability will be guaranteed.

Abstract: As the amount of scholarly communication increases, it is increasingly difficult for specific core scientific statements to be found, connected and curated. Additionally, the redundancy of these statements in multiple fora makes it difficult to determine attribution, quality and provenance. To tackle these challenges, the Concept Web Alliance has promoted the notion of nanopublications (core scientific statements with associated context). In this document, we present a model of nanopublications along with a Named Graph/RDF serialization of the model. Importantly, the serialization is defined completely using already existing community-developed technologies. Finally, we discuss the importance of aggregating nanopublications and the role that the Concept Wiki plays in facilitating it.

Abstract: A method of computing to address a predetermined computing requirement involving access to and use of computer resources, where more than one resource is capable of addressing the computing requirement. The method includes steps of describing plural computer resources using a description language, thereby obtaining descriptions of the resources; arranging the descriptions in one or more semantic ontologies; accessing one or more of the ontologies to select a particular one of the plural resources as available and/or qualified for addressing the computing requirement; and executing a computing process that utilizes the selected one of the plural resources to satisfy the computing requirement. The disclosed method involves use of description language and the computer resources comprise web services. The describing step involves identifying attributes of the computer-accessible resources. The attributes of the computer resources are selected from the group comprising but not limited to: message formatting for the computer resources, transport mechanisms associated with the computer resources, protocols associated with the computer resources, type serialization associated with the computer resources, and invocation requirements of the computer resources. In further accordance with the method, the invocation requirements of the computer resources may be selected from the group comprising: HTTP, SOAP, CORBA, JAVA RMI, and equivalent computer invocation specifications.