Transaction Support Research Articles

Transactional support for adaptive indexing

Adaptive indexing initializes and optimizes indexes incrementally, as a side effect of query processing. The goal is to achieve the benefits of indexes while hiding or minimizing the costs of index creation. However, index-optimizing side effects seem to turn read-only queries into update transactions that might, for example, create lock contention. This paper studies concurrency control and recovery in the context of adaptive indexing. We show that the design and implementation of adaptive indexing rigorously separates index structures from index contents; this relaxes constraints and requirements during adaptive indexing compared to those of traditional index updates. Our design adapts to the fact that an adaptive index is refined continuously and exploits any concurrency opportunities in a dynamic way. A detailed experimental analysis demonstrates that (a) adaptive indexing maintains its adaptive properties even when running concurrent queries, (b) adaptive indexing can exploit the opportunity for parallelism due to concurrent queries, (c) the number of concurrency conflicts and any concurrency administration overheads follow an adaptive behavior, decreasing as the workload evolves and adapting to the workload needs.

An analysis of deterring and facilitating factors in trade service business -on the basis of customs broker task-

During a decade, e-Commerce environments supporting real-time transaction processing have been getting larger. In telecommunication and financial environments, research and building for main memory database systems have been doing to support real-time transaction processing. A research on indexing for fast transaction support focuses on reducing cache misses or reducing memory access latency when cache misses happen. In the paper, we propose a prefetch method for tree index structures to reduce memory access latency. We present a prefetch-efficient pCST-tree and show superiority of the proposed tree by experiments.

Autism and multidisciplinary teamwork through the SCERTS Model

This research investigates multidisciplinary teamwork in an English special school located in the West Midlands region of the UK. The research was carried out by Paola Molteni, a PhD student at Università Cattolica del Sacro Cuore, Milan, Karen Guldberg of the Autism Centre for Education and Research Director at the University of Birmingham School of Education, and Nick Logan, head of the Psychology and Therapists Department at Sunfield Children's Home, Clent. The school uses the innovative SCERTS (Social Communication, Emotional Regulation, Transactional Support) model. The methodology was a collaborative and participatory case study focused on the point of view of professionals and on understanding the teamwork process through analysis of three teams working together to implement SCERTS. Methods included focus groups, semi‐structured interviews, direct observations and questionnaires; the data were analysed using the Interpretative Phenomenological Analysis method. The research provides an example of good practice and enables practitioners to reflect on the issues involved in implementing a multidisciplinary process using the SCERTS approach. The findings show that the SCERTS Model can support the educational team in promoting and exchanging good daily practice and planning educational work together. The article draws out implications for further studies that aim to analyse teamwork in other settings and over a longer period.

DeAliaser

Alias analysis is a critical component in many compiler optimizations. A promising approach to reduce the complexity of alias analysis is to use speculation. The approach consists of performing optimizations assuming the alias relationships that are true most of the time, and repairing the code when such relationships are found not to hold through runtime checks. This paper proposes a general alias speculation scheme that leverages upcoming hardware support for transactions with the help of some ISA extensions. The ability of transactions to checkpoint and roll back frees the compiler to pursue aggressive optimizations without having to worry about recovery code. Also, exposing the memory conflict detection hardware in transactions to software allows runtime checking of aliases with little or no overhead. We test the potential of the novel alias speculation approach with Loop Invariant Code Motion (LICM), Global Value Numbering (GVN), and Partial Redundancy Elimination (PRE) optimization passes. On average, they are shown to reduce program execution time by 9% in SPEC FP2006 applications and 3% in SPEC INT2006 applications over the alias analysis of a state-of-the-art compiler.

DeAliaser

Alias analysis is a critical component in many compiler optimizations. A promising approach to reduce the complexity of alias analysis is to use speculation. The approach consists of performing optimizations assuming the alias relationships that are true most of the time, and repairing the code when such relationships are found not to hold through runtime checks. This paper proposes a general alias speculation scheme that leverages upcoming hardware support for transactions with the help of some ISA extensions. The ability of transactions to checkpoint and roll back frees the compiler to pursue aggressive optimizations without having to worry about recovery code. Also, exposing the memory conflict detection hardware in transactions to software allows runtime checking of aliases with little or no overhead. We test the potential of the novel alias speculation approach with Loop Invariant Code Motion (LICM), Global Value Numbering (GVN), and Partial Redundancy Elimination (PRE) optimization passes. On average, they are shown to reduce program execution time by 9% in SPEC FP2006 applications and 3% in SPEC INT2006 applications over the alias analysis of a state-of-the-art compiler.

Cloud Platform Datastore Support

There are many datastore systems to choose from that differ in many ways including public versus private cloud support, data management interfaces, programming languages, supported feature sets, fault tolerance, consistency guarantees, configuration, and their deployment processes. In this paper, we focus on technologies for structured data access (database/datastore systems) in cloud systems. Our goal is to simplify the use of datastore systems through automation and to facilitate their empirical evaluation using real world applications. To enable this, we provide a cloud platform abstraction layer that decouples a data access API from its implementation. Applications that use this API can use any datastore that “plugs into” our abstraction layer, thus enabling application portability. We use this layer to extend the functionality of multiple datastores without modifying the datastores directly. Specifically, we provide support for ACID transaction semantics for popular key-value stores (none of which provide this feature). We integrate this layer into the AppScale cloud platform—an open-source cloud platform that executes cloud applications written in Python, Java, and Go, over virtualized cluster resources and infrastructures-as-a-service (Eucalyptus, OpenStack, and Amazon EC2). We use this system to investigate the impact of extending disparate datastores via the application portability layer with distributed transaction support.

Design and Promotion Strategy of Marketing Platform of Aquatic Auction based on Internet

For the online trade and promotion of aquatic products and related materials through the network between supply and demand, the design content and effective promotional strategies of aquatic auctions online marketing platform is proposed in this paper. Design elements involve the location of customer service, the basic function of the platform including the purchase of general orders, online auctions, information dissemination, and recommendation of fine products, human services, and payment preferences. Based on network and mobile e-commerce transaction support, the auction platform makes the transaction of aquatic products well in advance. The results are important practical value for the design and application of online marketing platform of aquatic auction.

A framework for ensuring consistency of Web Services Transactions based on WS-BPEL

(9-11) . These specifications provide transaction support in loose coupling environment by relaxing ACID properties of traditional transaction. BTP adopt the two-phase commit protocol to ensure the consistency of the transaction, but it's not very ideal in practice because its centralization management and it doesn't support traditional ACID transaction. The WS-Transaction describes an extensible framework for divorcing the coordination framework and coordination type. But two kind coordination types that are proposed lack of implementation of concrete coordinate process. WS-CAF has certain advantage compare with the former two specifications. It is similar to WS-Transaction, but more completed, however, the WS-CAF has not adopted by any system recently. WS-BPEL is a mainstream web service composition description language and has become a standard description language. WS-BPEL relied on WSDL is defined as an process-oriented service composition language based on XML ,and is formulated into a norm for web service composition. It can not only implement combination, interaction and presentation process between web services but also WS-BPEL process itself is exposed as a WSDL-defined services and can be called by other web services. The core concept of WS-BPEL is active, that is a statement or a step in the implementation during the WS- BPEL process.The activity of BPEL is divided into atomic activity and structured activity. The atomic activity such as invoke, reply,receive,assign and so on ,which is used for calling a partner web service and the structured activities such as scope, sequence, flow

Quantitative Evaluation of the Relationship BetweenSupply and Off-Take Contracts in Petroleum Refinery Projects Utilizing Project Finance

The petroleum industry is one of the fastest growing sectors in the world in terms of private participation and financing. The risk and uncertainty associated with the crude oil supply and product demand influence the overall economic viability of petroleum refinery projects. Issues associated with the security of a project’s cash flow are of primary concern to investors using project finance in the procurement of petroleum refineries. This article reviews the characteristics of petroleum refinery projects, the concept of project finance, and issues associated with its application, with emphasis on the investigation and appraisal of the arrangement of supply and off-take contracts in relation to risks and economic returns. A mechanism is developed to aid contractual arrangements of supply and off-take strategies in support of project finance transactions in the procurement of petroleum refineries. The mechanism is tested in a case study through computer simulation.

Engaging students in learning: a review of a conceptual organiser

Student engagement in learning is a complex process influenced by many factors. This article introduces a conceptual organiser developed from a review of the literature. It captures four key perspectives – motivation and agency, transactional engagement, institutional support and active citizenship – and suggested indicators for each perspective. Data from a project researching student engagement with first‐time enrolled students in Aotearoa New Zealand is then used to review the conceptual organiser. Findings show that the four perspectives were all evident, though some indicators were more clearly supported than others. As a result of the evaluation, changes were made to the organiser. We argue that it has value as a way for teachers and institutions to inform and evaluate their efforts to engage students in learning.

The Effect of Information Technology Investments in Healthcare: A Longitudinal Study of its Lag, Duration, and Economic Value

This research develops a framework that disaggregates investments in IT in the healthcare industry into four distinct categories: investments in patient management IT (PMIT), transactional support IT (TSIT), communications IT (CIT), and administrative IT (AIT). In a longitudinal study, financial and operational data from several hospitals spanning 26 years are analyzed to examine the lag as well as duration of the effect of these IT investments on hospital costs and labor productivity. The results reveal that TSIT capital has an immediate effect on medical labor and administrative labor productivities, and a lagged but durable effect on operating costs. CIT capital has an immediate but short-term effect on medical labor and administrative labor productivities. AIT capital has an immediate but short-term effect on medical labor productivity. PMIT capital, on the other hand, increases operating costs, an effect that is immediate but short-term. Finally, post hoc marginal analysis reveals that among the four types of IT investments, CIT has the maximum economic value effect on hospital productivity, followed by TSIT, and then AIT; with PMIT having a minimal economic value effect.

An Interview with Emily Rubin

An Interview with Emily Rubin

Rule-based service charging method for composite services

How to achieve accurate and fair benefit sharing amongst service providers is a key issue in the sustainable development of SOA-based operating platforms. The realisation of this goal necessitates an efficient, flexible, and scalable service charging solution. Charging for composite services is more complex than that for traditional services because in the former, more factors including the sub-services provided by different providers, service exceptions, and sub-service updating are considered. This paper presents a rule-based charging method for composite services. Chained composite service and network-like composite service based on abstract charging actions are proposed. Through these services, the charging state diagram and charging cycle management in the charging service caller layer are achieved. Exception handling and recovery solutions are also discussed, along with the support of the rule engine transaction in the charging service implementation layer. The experiment shows that the proposed charging system can fulfil the requirements of charging services.

Modeling and preventing TOCTTOU vulnerabilities in Unix-style file systems

TOCTTOU (Time-of-Check-To-Time-Of-Use) is a file-based race condition in Unix-style systems and characterized by a pair of file object access by a vulnerable program: a check operation establishes certain conditions about the file object (e.g., the file exists), followed by a use operation that assumes that the established condition still holds. Due to the lack of support for transactions in Unix-style file systems, an attacker can modify the established file condition in-between the check and use steps, thus causing significant harm. In this paper, we present a model of the TOCTTOU problem (called STEM), which enumerates all the potential file system call pairs (called exploitable TOCTTOU pairs) that form the check/use steps. The model shows that a successful TOCTTOU attack requires a change in the mapping of pathname to logical disk blocks between the check and use steps. We apply STEM to POSIX and Linux to demonstrate its practical value for Unix-style file systems. Then we propose a defense mechanism (called EDGI) that prevents an attacker from tampering with the file condition between exploitable TOCTTOU pairs during a vulnerable program’s execution. EDGI works at the file system level and does not require existing applications to change. We have implemented EDGI on Linux kernel 2.4.28 and our evaluation shows that EDGI is effective and incurs little overhead to application benchmarks such as Andrew and Postmark.

From a stream of relational queries to distributed stream processing

Applications from several domains are now being written to process live data originating from hardware and software-based streaming sources. Many of these applications have been written relying solely on database and data warehouse technologies, despite their lack of need for transactional support and ACID properties. In several extreme high-load cases, this approach does not scale to the processing speeds that these applications demand. In this paper we demonstrate an application acceleration approach whereby a regular ODBC-based application is converted into a true streaming application with minimal disruption from a software engineering standpoint. We showcase our approach on three real-world applications. We experimentally demonstrate the substantial performance improvements that can be observed when contrasting the accelerated implementation with the original database-oriented implementation.

Log-based middleware server recovery with transaction support

Providing enterprises with reliable and available Web-based application programs is a challenge. Applications are traditionally spread over multiple nodes, from user (client), to middle tier servers, to back end transaction systems, e.g. databases. It has proven very difficult to ensure that these applications persist across system crashes so that "exactly once" execution is produced, always important and sometimes essential, e.g., in the financial area. Our system provides a framework for exactly once execution of multi-tier Web applications, built on a commercially available Web infrastructure. Its capabilities include low logging overhead, recovery isolation (independence), and consistency between mid-tier and transactional back end. Good application performance is enabled via persistent shared state in the middle tier while providing for private session state as well. Our extensive experiments confirm both the desired properties and the good performance.

Children with Autism Spectrum Disorders: Three Case Studies

Children with Autism Spectrum Disorders: Three Case Studies

Rule-Based Coordination of Distributed Web Service Transactions

Current approaches to transactional support of distributed processes in service-oriented environments are limited to scenarios where the participant initiating the process maintains a controlling position throughout the lifetime of the process. This constraint impedes support of complex processes where participants may only possess limited local views on the overall process. Furthermore, there is little support of dynamic aspects: failure or exit of participants usually leads to cancelation of the whole process. In this paper, we address these limitations by introducing a framework that strengthens the role of the coordinator and allows for largely autonomous coordination of dynamic processes. We first discuss motivating examples and analyze existing approaches to transactional coordination. Subsequently, we present our framework TracG, which is based on WS-BusinessActivity. It contains at its core a set of rules for deciding on the ongoing confirmation or cancelation status of participants' work and protocol extensions for monitoring the progress of a process. Various types of participant vitality for a process are distinguished, facilitating the controlled exit of nonvital participants as well as continuation of a process in case of tolerable failures. The implementation of the framework is presented and discussed regarding interoperability issues.

Using the SCERTS Model Assessment Tool to Identify Music Therapy Goals for Clients with Autism Spectrum Disorder

The purposes of this paper were to identify and compare goals and objectives addressed by music therapists that are contained in the SCERTS Model, for use with children at risk or diagnosed with a communication impartment including Autism Spectrum Disorder (ASD). A video analysis of music therapists working with clients at risk or diagnosed with ASD (N = 33) was conducted to: (a) identify the areas of the SCERTS assessment model that music therapists are currently addressing within their sessions for clients with ASD, and (b) compare the frequency of SCERTS domains and goals addressed by music therapists within sessions. Results of the analysis revealed that all three domains of social communication, emotional regulation, and transactional support were addressed within music therapy sessions. Within each domain both broad goals were all addressed including joint attention and symbol use for social communication, self-regulation and mutual regulation for emotional regulation, and interpersonal support and learning support for transactional support. Overall, music therapists addressed transactional support goals and subgoals more often than social communication and emotional regulation goals and subgoals. The highest frequency goal area addressed was interpersonal support (73.96%) and the lowest goal area addressed was joint attention (35.96%). For the social partner and language partner language stages, 58 of the 320 possible subgoals were addressed with 90% frequency or higher, while 13 of the same subgoals were never addressed. The SCERTS Model is designed for use by a multidisciplinary team of professionals and family members throughout a client's treatment and contains an ongoing assessment tool with resulting goals and objectives. This analysis indicates that many SCERTS goals and objectives can be addressed in music therapy interventions. Additionally, goals and subgoals not previously recognized in music therapy treatment can be generated by the use of the SCERTS Model.

A Framework Describing the Relationships among Social Technologies and Social Capital Formation in Electronic Entrepreneurial Networking

E-commerce technologies—including online exchanges—focus heavily on transaction support. They are designed primarily to reduce transaction costs between suppliers, producers, distributors, and customers. Entrepreneurs however are not likely to realize the full business potential of e-commerce unless the transaction technologies are simultaneously supported by technology-enabled social learning networks used to stimulate the formation of social capital in its three primary manifestations. Toward that end this article argues that a number of Internet-based social technologies (e.g., email, chat, blogs, wikis, podcasts, etc.) can be used more effectively when it is understood that each technology offers different characteristics in support of the formation of different dimensions of social capital. This article presents a conceptual framework describing the capacities of various social technologies for supporting the formation of social capital. A primary thrust of the article is that alignment of a social technology infrastructure with the social capital requirements in entrepreneurial communities will facilitate the formation of electronic learning networks, enabling more collaborative and therefore more successful entrepreneurial communities.