The Experts below are selected from a list of 63351 Experts worldwide ranked by ideXlab platform
Neil Tennant - One of the best experts on this subject based on the ideXlab platform.
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New foundations for a Relational Theory of Theory-revision
Journal of Philosophical Logic, 2006Co-Authors: Neil TennantAbstract:AGM-Theory, named after its founders Carlos Alchourron, Peter Gardenfors and David Makinson, is the leading contemporary paradigm in the Theory of belief-revision. The Theory is reformulated here so as to deal with the central Relational notions ‘J is a contraction of K with respect to A’ and ‘J is a revision of K with respect to A’. The new Theory is based on a principal-case analysis of the domains of definition of the three main kinds of Theory-change (expansion, contraction and revision). The new Theory is stated by means of introduction and elimination rules for the Relational notions. In this new setting one can re-examine the relationship between contraction and revision, using the appropriate versions of the so-called Levi and Harper identities. Among the positive results are the following. One can derive the extensionality of contraction and revision, rather than merely postulating it. Moreover, one can demonstrate the existence of revision-functions satisfying a principle of monotonicity. The full set of AGM-postulates for revision-functions allow for completely bizarre revisions. This motivates a Principle of Minimal Bloating, which needs to be stated as a separate postulate for revision. Moreover, contractions obtained in the usual way from the bizarre revisions, by using the Harper identity, satisfy Recovery. This provides a new reason (in addition to several others already adduced in the literature) for thinking that the contraction postulate of Recovery fails to capture the Principle of Minimal Mutilation. So the search is still on for a proper explication of the notion of minimal mutilation, to do service in both the Theory of contraction and the Theory of revision. The new Relational formulation of AGM-Theory, based on principal-case analysis, shares with the original, functional form of AGM-Theory the idealizing assumption that the belief-sets of rational agents are to be modelled as consistent, logically closed sets of sentences. The upshot of the results presented here is that the new Relational Theory does a better job of making important matters clear than does the original functional Theory. A new setting has been provided within which one can profitably address two pressing questions for AGM-Theory: (1) how is the notion of minimal mutilation (by both contractions and revisions) best analyzed? and (2) how is one to rule out unnecessary bloating by revisions?
C. J. Date - One of the best experts on this subject based on the ideXlab platform.
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Time and Relational Theory, Second Edition: Temporal Databases in the Relational Model and SQL
2014Co-Authors: C. J. Date, Hugh Darwen, Nikos A. LorentzosAbstract:Time and Relational Theory provides an in-depth description of temporal database systems, which provide special facilities for storing, querying, and updating historical and future data. Traditionally, database management systems provide little or no special support for temporal data at all. This situation is changing because: Cheap storage enables retention of large volumes of historical data in data warehouses Users are now faced with temporal data problems, and need solutions Temporal features have recently been incorporated into the SQL standard, and vendors have begun to add temporal support to their DBMS products Based on the groundbreaking text Temporal Data & the Relational Model (Morgan Kaufmann, 2002) and new research led by the authors, Time and Relational Theory is the only book to offer a complete overview of the functionality of a temporal DBMS. Expert authors Nikos Lorentzos, Hugh Darwen, and Chris Date describe an approach to temporal database management that is firmly rooted in classical Relational Theory and will stand the test of time. This book covers the SQL:2011 temporal extensions in depth and identifies and discusses the temporal functionality still missing from SQL. Understand how the Relational model provides an ideal basis for taming the complexities of temporal databases Learn how to analyze and evaluate commercial temporal products with this timely and important information Be able to use sound principles in designing and using temporal databases Understand the temporal support recently added to SQL with coverage of the new SQL features in this unique, accurate, and authoritative reference Appreciate the benefits of a truly Relational approach to the problem with this clear, user friendly presentation
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Relational Theory for Computer Professionals
2013Co-Authors: C. J. DateAbstract:All of todays mainstream database products support the SQL language, and Relational Theory is what SQL is supposed to be based on. But are those products truly Relational? Sadly, the answer is no. This book shows you what a real Relational product would be like, and how and why it would be so much better than whats currently available.With this unique book, you will:Learn how to see database systems as programming systems Get a careful, precise, and detailed definition of the Relational model Explore a detailed analysis of SQL from a Relational point of view There are literally hundreds of books on Relational Theory or the SQL language or both. But this one is different. First, nobody is more qualified than Chris Date to write such a book. He and Ted Codd, inventor of the Relational model, were colleagues for many years, and Chriss involvement with the technology goes back to the time of Codds first papers in 1969 and 1970. Second, most books try to use SQL as a vehicle for teaching Relational Theory, but this book deliberately takes the opposite approach. Its primary aim is to teach Relational Theory as such. Then it uses that Theory as a vehicle for teaching SQL, showing in particular how that Theory can help with the practical problem of using SQL correctly and productively.Any computer professional who wants to understand what Relational systems are all about can benefit from this book. No prior knowledge of databases is assumed.
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database design and Relational Theory normal forms and all that jazz
2012Co-Authors: C. J. DateAbstract:What makes this book different from others on database design? Many resources on design practice do little to explain the underlying Theory, and books on design Theory are aimed primarily at theoreticians. In this book, renowned expert Chris Date bridges the gap by introducing design Theory in ways practitioners can understanddrawing on lessons learned over four decades of experience to demonstrate why proper database design is so critical in the first place.Every chapter includes a set of exercises that show how to apply the theoretical ideas in practice, provide additional information, or ask you to prove some simple theoretical result. If youre a database professional familiar with the Relational model, and have more than a passing interest in database design, this book is for you.Questions this book answers include:Why is Heaths Theorem so important? What is The Principle of Orthogonal Design? What makes some JDs reducible and others irreducible? Why does dependency preservation matter? Should data redundancy always be avoided? Can it be? Databases often stay in production for decades, and careful design is critical for avoiding subtle errors and processing problems over time. If theyre badly designed, the negative impacts can be incredibly widespread. This gentle introduction shows you how to use important theoretical results to create good database designs.
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C.j. date's sql and Relational Theory master class
2010Co-Authors: C. J. DateAbstract:Chris Date is the world's best known Relational advocate. In this online seminar, he shows how to write SQL code that's logically correct; how to avoid various SQL traps and pitfalls; and, more generally, how to use SQL as if it were a true Relational language. Appreciate how Relational principles provide SQL's logical underpinnings. Understand the breadth and depth of those principles. Know how to formulate complex SQL code with confidence that it's correct. Be able to use SQL Relationally. SQL is ubiquitous. But SQL is also complicated, difficult, and error prone -- much more so than SQL advocates would have you believe. There's a lot of bad practice in the way SQL is used, and testing SQL can never be exhaustive. If you have any hope of writing correct SQL, you must follow some discipline: the discipline of using SQL Relationally. It's a fact: SQL is the standard language for Relational databases, but that doesn't make it Relational! SQL departs from Relational Theory in all too many ways. Duplicate rows and nulls provide two obvious examples, but they're not the only ones. In this class, you'll learn Relational Theory, how SQL departs from the Theory, and how to avoid the problems that can cause. By using the Relational model as an organizing principle, and learning various features of the model in depth, you'll discover the best ways to implement SQL. And you'll enjoy the benefits of working with a truly Relational system. Exercises are an integral part of the class, and your discussion and interaction are encouraged. We are capturing these sessions on video and all students are required to sign a release form prior to the commencement of the class, a copy of which may be downloaded in advance. Hard copy forms will be provided at the event.
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SQL and Relational Theory: How to Write Accurate SQL Code
2009Co-Authors: C. J. DateAbstract:SQL is full of difficulties and traps for the unwary. You can avoid them if you understand Relational Theory, but only if you know how to put the Theory into practice. In this insightful book, author C.J. Date explains Relational Theory in depth, and demonstrates through numerous examples and exercises how you can apply it directly to your use of SQL.This second edition includes new material on recursive queries, missing information without nulls, new update operators, and topics such as aggregate operators, grouping and ungrouping, and view updating. If you have a modest-to-advanced background in SQL, youll learn how to deal with a host of common SQL dilemmas.Why is proper column naming so important? Nulls in your database are causing you to get wrong answers. Why? What can you do about it? Is it possible to write an SQL query to find employees who have never been in the same department for more than six months at a time? SQL supports quantified comparisons, but theyre better avoided. Why? How do you avoid them? Constraints are crucially important, but most SQL products dont support them properly. What can you do to resolve this situation? Database Theory and practice have evolved since the Relational model was developed more than 40 years ago. SQL and Relational Theory draws on decades of research to present the most up-to-date treatment of SQL available. C.J. Date has a stature that is unique within the database industry. A prolific writer well known for the bestselling textbook An Introduction to Database Systems (Addison-Wesley), he has an exceptionally clear style when writing about complex principles and Theory.
Sandya Hewamanne - One of the best experts on this subject based on the ideXlab platform.
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Categorical Variables Without Categorical Thinking? A Relational Reading of the Sri Lankan Demographic and Health Survey
Gender Issues, 2020Co-Authors: Catherine E. Harnois, Sandya HewamanneAbstract:Connell’s Theory of gender relations is among the most influential and comprehensive frameworks for analyzing gender. Its influence across methodological approaches has been uneven, though, and Connell herself has argued that Relational Theory is incompatible with statistical analyses, which, by relying on categorical dummy variables to indicate the sex or gender respondents, essentialize and fundamentally misrepresent gender. We argue that categorical variables do not require “categorical thinking.” We outline three necessary steps for linking statistical analyses and Relational Theory: contextualizing statistical rates and means; highlighting within-group variation and the process through which it is produced; and contextualizing the data collection and research process more broadly. To illustrate our approach we critically examine data from the 2006–2007 Sri Lanka Demographic and Health Survey. We show that, far from being incompatible, Relational Theory is often vital for understanding the meaning of statistical data, as well as for critiquing and evaluating any resulting claims. When interpreted within a Relational framework, statistical data can also clarify how gender structures the lives and experiences of people of all genders.
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categorical variables without categorical thinking a Relational reading of the sri lankan demographic and health survey
Gender Issues, 2020Co-Authors: Catherine E. Harnois, Sandya HewamanneAbstract:Connell’s Theory of gender relations is among the most influential and comprehensive frameworks for analyzing gender. Its influence across methodological approaches has been uneven, though, and Connell herself has suggested that Relational Theory is incompatible with statistical analyses, which, by relying on categorical dummy variables to indicate the sex or gender respondents, essentialize and fundamentally misrepresent gender. We argue that categorical variables do not require “categorical thinking.” We outline three necessary steps for linking statistical analyses and Relational Theory: contextualizing statistical rates and means; highlighting within-group variation and the process through which it is produced, and contextualizing the data collection and research process more broadly. To illustrate our approach we critically examine data from the 2006-2007 Sri Lanka Demographic and Health Survey. We show that, far from being incompatible, Relational Theory is often vital for understanding the meaning of statistical data, as well as for critiquing and evaluating any resulting claims. When interpreted within a Relational framework, statistical data can also clarify how gender structures the lives and experiences of people of all genders.
Nooch Kuasirikun - One of the best experts on this subject based on the ideXlab platform.
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Gifting, Exchange and Reciprocity in Thai Annual Reports: Towards a Buddhist Relational Theory of Thai Accounting Practice
Critical Perspectives on Accounting, 2018Co-Authors: Philip Constable, Nooch KuasirikunAbstract:Abstract This paper analyses the inter-relationship of human agency and socio-economic structure in the determination of Thai accounting. It demonstrates that determination of accounting practice lies neither in the individual agency of human practice, nor in the forces of socio- economic structure per se, but rather in patterns of Relational practice. Drawing on the theoretical framework of Mauss (1925) to analyse accounting practice as revealed in Thai company annual reports, this paper elaborates a Buddhist Relational Theory of accounting practice that focuses on the importance of patterns of practice generated by gifting, exchange and reciprocity. It studies the ways that accounting as evidenced in the Relational practices of Thai annual reports creates patterns of corporate, societal and state identity in late 20th and early 21st-century Thailand. The article also relates this Thai Buddhist conceptualisation of practice to other theoretical approaches, particularly Foucault, Giddens and Latour, which accounting historians have adapted to express the interaction of human and structural agency in practice. In doing so, the paper seeks to highlight some of the limitations in such accounting theorisation and emphasise the importance of a focus on normative patterns of Relational practice as an explanation of accounting formation.
Catherine E. Harnois - One of the best experts on this subject based on the ideXlab platform.
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Categorical Variables Without Categorical Thinking? A Relational Reading of the Sri Lankan Demographic and Health Survey
Gender Issues, 2020Co-Authors: Catherine E. Harnois, Sandya HewamanneAbstract:Connell’s Theory of gender relations is among the most influential and comprehensive frameworks for analyzing gender. Its influence across methodological approaches has been uneven, though, and Connell herself has argued that Relational Theory is incompatible with statistical analyses, which, by relying on categorical dummy variables to indicate the sex or gender respondents, essentialize and fundamentally misrepresent gender. We argue that categorical variables do not require “categorical thinking.” We outline three necessary steps for linking statistical analyses and Relational Theory: contextualizing statistical rates and means; highlighting within-group variation and the process through which it is produced; and contextualizing the data collection and research process more broadly. To illustrate our approach we critically examine data from the 2006–2007 Sri Lanka Demographic and Health Survey. We show that, far from being incompatible, Relational Theory is often vital for understanding the meaning of statistical data, as well as for critiquing and evaluating any resulting claims. When interpreted within a Relational framework, statistical data can also clarify how gender structures the lives and experiences of people of all genders.
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categorical variables without categorical thinking a Relational reading of the sri lankan demographic and health survey
Gender Issues, 2020Co-Authors: Catherine E. Harnois, Sandya HewamanneAbstract:Connell’s Theory of gender relations is among the most influential and comprehensive frameworks for analyzing gender. Its influence across methodological approaches has been uneven, though, and Connell herself has suggested that Relational Theory is incompatible with statistical analyses, which, by relying on categorical dummy variables to indicate the sex or gender respondents, essentialize and fundamentally misrepresent gender. We argue that categorical variables do not require “categorical thinking.” We outline three necessary steps for linking statistical analyses and Relational Theory: contextualizing statistical rates and means; highlighting within-group variation and the process through which it is produced, and contextualizing the data collection and research process more broadly. To illustrate our approach we critically examine data from the 2006-2007 Sri Lanka Demographic and Health Survey. We show that, far from being incompatible, Relational Theory is often vital for understanding the meaning of statistical data, as well as for critiquing and evaluating any resulting claims. When interpreted within a Relational framework, statistical data can also clarify how gender structures the lives and experiences of people of all genders.
