Design issues in XML formats
|
|
- Ilene Peters
- 5 years ago
- Views:
Transcription
1 Design issues in XML formats David Mertz, Ph.D. Gesticulator, Gnosis Software, Inc. 1 November 2001 In this tip, developerworks columnist David Mertz advises when to use tag attributes and when to use subelement contents to represent data. Learn what considerations go into designing a DTD, Schema, or just an ad hoc XML format. You'll also learn when attributes and contents are interchangeable, and when they aren't. Code samples show the options. An odd thing about XML is that it provides two almost, but not quite, equivalent ways of spelling "this is the data." One way to indicate a data value is to put it inside a subelement; another way is to put it in attribute values. Because there usually isn't an obvious answer for when of each of the two approaches is appropriate, XML is not entirely orthogonal (which is computer science speak for "each construct does one thing, and no other construct does the same thing"). This tip offers some guidance for when to use subelements and when to use attributes. One time when you do not need to decide what data goes where is when you are handed an XML dialect specification to follow -- given to you as a DTD or as a W3C XML Schema, or described informally or by example. If you are not making the choices, don't worry about the suggestions in this tip. Often, though, developers need to design the exact XML dialect to use for a process. If that's your case, read on. One thing to keep in mind is the difference between XML documents that merely need to be well formed, and those that need to be valid relative to some DTD/Schema. Validity is much more rigorous; it allows you to insist that certain data be present and be structured in a certain way. For the very same reason, it is much more work to make sure a given document production process conforms with validity requirements. Both approaches have advantages; imposing a DTD adds complexity to the element/attribute issue, but there are tradeoffs in both cases. These tradeoffs are discussed below. Is data order important? If you want to use a DTD, subelements are strictly ordered, while attributes are unordered. In well-formed-only XML documents, you are free to play with order; after all, in this case any tag can go inside any other tag, at any depth. In both cases, attributes are usually better for unordered data. For XML documents with a DTD, however, use of attributes is almost required for this type of data For example, you might have a list of contacts, each of whom must have a name, age, and telephone number. But there is no logical sense in which age precedes telephone 1
2 number. The attributes are thus unordered. In this case, attributes are more intuitive. Compare the brief XML documents in listings 1 and 2: Listing 1. Attribute data for contacts <?xml version="1.0"?> <!DOCTYPE contacts SYSTEM "attrs.dtd" > <contacts> <contact name="jane Doe" age="74" telephone=" " /> <contact name="chieu Win" telephone=" " age="44" /> </contacts> Listing 2. Subelement data for contacts <?xml version="1.0"?> <!DOCTYPE contacts SYSTEM "subelem.dtd" > <contacts> <contact> <name>jane Doe</name> <age>74</age> <telephone> </telephone> </contact> <contact> <name>chieu Win</name> <telephone> </telephone> <age>44</age> </contact> </contacts> Imagine the DTD that is implied by each XML format. For the attribute-oriented form in Listing 1, it might look like Listing 3. Listing 3. Attribute DTD for contacts document <!ELEMENT contacts (contact*)> <!ELEMENT contact EMPTY> <!ATTLIST contact name CDATA #REQUIRED age CDATA #REQUIRED telephone CDATA #REQUIRED > A subelement-oriented DTD to do the same thing could look like Listing 4. 2
3 Listing 4. Subelement DTD for contacts document <!ELEMENT contacts (contact*)> <!ELEMENT contact (name,age,telephone)> <!ELEMENT name (#PCDATA)> <!ELEMENT age (#PCDATA)> <!ELEMENT telephone (#PCDATA)> The obvious problem with the DTD in Listing 4 is that the simple example in Listing 2 is invalid under the DTD (even though it has the data we want). The subelements are out of order. The sidebar shows how you can use unordered subelements with a DTD, but unless there is a different compelling reason, it is better to use the attribute-style for unordered data. Does multiple data occur at the same level? If the same type of data occurs many times within an object, subelements win, hands down. For example, in the contact list scenario, a contacts object contains many contact objects. In this case, it is clear that each contact should be described within a child element of the contacts element. In real life, however, developers often creep away from this design principle in the course of making revisions. Here is how it happens: First, you find that each Flazbar has a flizbam attached to it (and a flizbam is described by a datum). Good enough, it seems like an obvious choice to save the extra verbosity of a subelement and create a flizbam attribute for the Flazbar tag. A while down the road -- after you have written wonderful production code for handling Flazbars -- you discover that in some situations a Flazbar can have two flizbams. Not a problem: with very little change to your installed code, you just change the DTD to contain: <!ATTLIST Flazbar flizbam CDATA #REQUIRED flizbam2 CDATA #IMPLIED> With the amended code, your old XML documents are still valid, but new ones work also. After a while you discover the third flizbam... It's hard to avoid being tempted into this design pitfall. Data and objects evolve over time, and singular things frequently become dual or multiple. Some XML programmers eschew attributes altogether for this reason, but I think that goes too far. My advice is to think carefully at the design stage about whether a singular datum might have siblings later on. If there is a reasonable probability of multiple siblings in the future, use subelements from the start. If you can be reasonably confident that a data object will remain unique, stick with attributes. 3
4 Is whitespace preservation required? After normalization of attributes, you can count on every token in an attribute being separated from its neighbors by whitespace. But that's all you can count on. For readability by developers, you can add vertical and horizontal whitespace to long attribute values without any problem (in fact, you should do this). But once those readable attributes go through an XML parser, the layout of the attribute will probably be somewhat different than in the source XML. If whitespace is important, subelements are a better choice. For instance, if you are representing something like source code or poetry, where exact spacing matters, stick to element contents. Does readability count? Ideally, XML should be a format computers read, not one humans read. But, fortunately or unfortunately, programmers are humans too; and for the foreseeable future, we are going to spend a lot of time reading, writing, and debugging XML files. It is positively painful to read XML that is formatted with only machines in mind (no whitespace, or nonsensical whitespace). Personally, I find it much easier to read and write attributeoriented XML formats than subelement-oriented ones. Look again at Listing 1 and Listing 2 above to see what I mean. Neither is horrible to read, but the attribute version in Listing 2 is easier -- and better still to write, because you do not need to worry about capricious subelement ordering. Conclusion I have pointed to some cases where subelements or attributes are more desirable. Keeping in mind the principles addressed can lead to clearer and cleaner XML document formats. Unfortunately, sometimes the real situation falls into multiple cases (pointing in opposite directions). And a lot of times, data designs change enough to invalidate previous motivations. Use the rules given in this tip where possible, but above all "use (informed) common sense." Resources Simulating unordered subelements You could create a DTD that makes the XML document in Listing 2 valid by including the definition, as in this listing. A DTD that defines contact list subelements very flexibly However, the DTD above allows far too much flexibility. You could have contact elements with no name, and ones with several ages -- neither of which meets the semantic requirements. To get what we really want would require the extremely cumbersome definition below. A cumbersome but accurate DTD for contact list elements This DTD is ugly, and it gets uglier at a factorial rate with more data points. Plus, making a DTD stricter than is semantically necessary for data producers is also undesirable (for example, imposing the first subelement DTD). Everything you really need to know about XML is in the Extensible Markup Language (XML) 1.0 W3C Recommendation. Of course, understanding exactly what this signifies requires some subtlety. The XML Cover Pages has some tips on Using elements and attributes. That page also contain pointers to a number of articles, each giving contrary advice about what criteria to use in deciding between attributes and elements. That is 4
5 why we programmers get paid the big bucks! One way to view the distinction between attributes and elements is in terms of "Document-Centric" vs. "Data-Centric" documents. Check out other XML tips published in the developerworks XML zone. About the author David Mertz uses a wholly unstructured brain to write about structured document formats. David may be reached at mertz@gnosis.cx; his life pored over at 5
Introduction Syntax and Usage XML Databases Java Tutorial XML. November 5, 2008 XML
Introduction Syntax and Usage Databases Java Tutorial November 5, 2008 Introduction Syntax and Usage Databases Java Tutorial Outline 1 Introduction 2 Syntax and Usage Syntax Well Formed and Valid Displaying
More informationChapter 2 XML, XML Schema, XSLT, and XPath
Summary Chapter 2 XML, XML Schema, XSLT, and XPath Ryan McAlister XML stands for Extensible Markup Language, meaning it uses tags to denote data much like HTML. Unlike HTML though it was designed to carry
More informationIntroduction to XML. XML: basic elements
Introduction to XML XML: basic elements XML Trying to wrap your brain around XML is sort of like trying to put an octopus in a bottle. Every time you think you have it under control, a new tentacle shows
More informationXML Structures. Web Programming. Uta Priss ZELL, Ostfalia University. XML Introduction Syntax: well-formed Semantics: validity Issues
XML Structures Web Programming Uta Priss ZELL, Ostfalia University 2013 Web Programming XML1 Slide 1/32 Outline XML Introduction Syntax: well-formed Semantics: validity Issues Web Programming XML1 Slide
More informationSemistructured data, XML, DTDs
Semistructured data, XML, DTDs Introduction to Databases Manos Papagelis Thanks to Ryan Johnson, John Mylopoulos, Arnold Rosenbloom and Renee Miller for material in these slides Structured vs. unstructured
More informationEMERGING TECHNOLOGIES. XML Documents and Schemas for XML documents
EMERGING TECHNOLOGIES XML Documents and Schemas for XML documents Outline 1. Introduction 2. Structure of XML data 3. XML Document Schema 3.1. Document Type Definition (DTD) 3.2. XMLSchema 4. Data Model
More informationOverview. Introduction. Introduction XML XML. Lecture 16 Introduction to XML. Boriana Koleva Room: C54
Overview Lecture 16 Introduction to XML Boriana Koleva Room: C54 Email: bnk@cs.nott.ac.uk Introduction The Syntax of XML XML Document Structure Document Type Definitions Introduction Introduction SGML
More informationLinked Lists. What is a Linked List?
Linked Lists Along with arrays, linked lists form the basis for pretty much every other data stucture out there. This makes learning and understand linked lists very important. They are also usually the
More informationA tutorial report for SENG Agent Based Software Engineering. Course Instructor: Dr. Behrouz H. Far. XML Tutorial.
A tutorial report for SENG 609.22 Agent Based Software Engineering Course Instructor: Dr. Behrouz H. Far XML Tutorial Yanan Zhang Department of Electrical and Computer Engineering University of Calgary
More informationIn our first lecture on sets and set theory, we introduced a bunch of new symbols and terminology.
Guide to and Hi everybody! In our first lecture on sets and set theory, we introduced a bunch of new symbols and terminology. This guide focuses on two of those symbols: and. These symbols represent concepts
More informationextensible Markup Language
extensible Markup Language XML is rapidly becoming a widespread method of creating, controlling and managing data on the Web. XML Orientation XML is a method for putting structured data in a text file.
More informationNotes on Turing s Theorem and Computability
Notes on Turing s Theorem and Computability Walter Neumann About 60 years ago there was a revolution in mathematics and philosophy. First Gödel and then Turing showed that there are impossible problems
More informationCPSC 320 Sample Solution, Playing with Graphs!
CPSC 320 Sample Solution, Playing with Graphs! September 23, 2017 Today we practice reasoning about graphs by playing with two new terms. These terms/concepts are useful in themselves but not tremendously
More informationIntroduction to XML Zdeněk Žabokrtský, Rudolf Rosa
NPFL092 Technology for Natural Language Processing Introduction to XML Zdeněk Žabokrtský, Rudolf Rosa November 28, 2018 Charles Univeristy in Prague Faculty of Mathematics and Physics Institute of Formal
More informationE-Guide Server hardware purchasing considerations
E-Guide Server hardware purchasing considerations Servers are expensive. When you re tasked with making a purchase of this size, you want to be sure you ve made the right choice especially as servers tend
More informationEXtensible Markup Language XML
EXtensible Markup Language XML 1 What is XML? XML stands for EXtensible Markup Language XML is a markup language much like HTML XML was designed to carry data, not to display data XML tags are not predefined.
More informationBinary, Hexadecimal and Octal number system
Binary, Hexadecimal and Octal number system Binary, hexadecimal, and octal refer to different number systems. The one that we typically use is called decimal. These number systems refer to the number of
More informationThe concept of DTD. DTD(Document Type Definition) Why we need DTD
Contents Topics The concept of DTD Why we need DTD The basic grammar of DTD The practice which apply DTD in XML document How to write DTD for valid XML document The concept of DTD DTD(Document Type Definition)
More informationCS103 Spring 2018 Mathematical Vocabulary
CS103 Spring 2018 Mathematical Vocabulary You keep using that word. I do not think it means what you think it means. - Inigo Montoya, from The Princess Bride Consider the humble while loop in most programming
More informationStructured documents
Structured documents An overview of XML Structured documents Michael Houghton 15/11/2000 Unstructured documents Broadly speaking, text and multimedia document formats can be structured or unstructured.
More information1 SEO Synergy. Mark Bishop 2014
1 SEO Synergy 2 SEO Synergy Table of Contents Disclaimer... 3 Introduction... 3 Keywords:... 3 Google Keyword Planner:... 3 Do This First... 4 Step 1... 5 Step 2... 5 Step 3... 6 Finding Great Keywords...
More informationBiocomputing II Coursework guidance
Biocomputing II Coursework guidance I refer to the database layer as DB, the middle (business logic) layer as BL and the front end graphical interface with CGI scripts as (FE). Standardized file headers
More informationWeek - 04 Lecture - 01 Merge Sort. (Refer Slide Time: 00:02)
Programming, Data Structures and Algorithms in Python Prof. Madhavan Mukund Department of Computer Science and Engineering Indian Institute of Technology, Madras Week - 04 Lecture - 01 Merge Sort (Refer
More informationPROFESSOR: Last time, we took a look at an explicit control evaluator for Lisp, and that bridged the gap between
MITOCW Lecture 10A [MUSIC PLAYING] PROFESSOR: Last time, we took a look at an explicit control evaluator for Lisp, and that bridged the gap between all these high-level languages like Lisp and the query
More informationHi everyone. I hope everyone had a good Fourth of July. Today we're going to be covering graph search. Now, whenever we bring up graph algorithms, we
Hi everyone. I hope everyone had a good Fourth of July. Today we're going to be covering graph search. Now, whenever we bring up graph algorithms, we have to talk about the way in which we represent the
More informationSemistructured Data and XML
Semistructured Data and XML Computer Science E-66 Harvard University David G. Sullivan, Ph.D. Structured Data The logical models we've covered thus far all use some type of schema to define the structure
More informationCSE 344 Midterm. November 9, 2011, 9:30am - 10:20am. Question Points Score Total: 100
CSE 344 Midterm November 9, 2011, 9:30am - 10:20am Name: Question Points Score 1 40 2 40 3 20 Total: 100 This exam is open book and open notes but NO laptops or other portable devices. You have 50 minutes;
More informationMITOCW watch?v=kz7jjltq9r4
MITOCW watch?v=kz7jjltq9r4 PROFESSOR: We're going to look at the most fundamental of all mathematical data types, namely sets, and let's begin with the definitions. So informally, a set is a collection
More informationXML Introduction 1. XML Stands for EXtensible Mark-up Language (XML). 2. SGML Electronic Publishing challenges -1986 3. HTML Web Presentation challenges -1991 4. XML Data Representation challenges -1996
More informationMITOCW watch?v=4dj1oguwtem
MITOCW watch?v=4dj1oguwtem PROFESSOR: So it's time to examine uncountable sets. And that's what we're going to do in this segment. So Cantor's question was, are all sets the same size? And he gives a definitive
More informationPart II: Semistructured Data
Inf1-DA 2011 2012 II: 22 / 119 Part II Semistructured Data XML: II.1 Semistructured data, XPath and XML II.2 Structuring XML II.3 Navigating XML using XPath Corpora: II.4 Introduction to corpora II.5 Querying
More informationConstructing a Document Type Definition (DTD) for XML
Constructing a Document Type Definition (DTD) for XML Abstract John W. Shipman 2013-08-24 12:16 Describes the Document Type Definition notation for describing the schema of an SGML or XML document type.
More information6.001 Notes: Section 15.1
6.001 Notes: Section 15.1 Slide 15.1.1 Our goal over the next few lectures is to build an interpreter, which in a very basic sense is the ultimate in programming, since doing so will allow us to define
More information.. Cal Poly CPE/CSC 366: Database Modeling, Design and Implementation Alexander Dekhtyar..
.. Cal Poly CPE/CSC 366: Database Modeling, Design and Implementation Alexander Dekhtyar.. XML in a Nutshell XML, extended Markup Language is a collection of rules for universal markup of data. Brief History
More informationTHE PRAGMATIC INTRO TO REACT. Clayton Anderson thebhwgroup.com WEB AND MOBILE APP DEVELOPMENT AUSTIN, TX
THE PRAGMATIC INTRO TO REACT Clayton Anderson thebhwgroup.com WEB AND MOBILE APP DEVELOPMENT AUSTIN, TX REACT "A JavaScript library for building user interfaces" But first... HOW WE GOT HERE OR: A BRIEF
More informationBST Deletion. First, we need to find the value which is easy because we can just use the method we developed for BST_Search.
BST Deletion Deleting a value from a Binary Search Tree is a bit more complicated than inserting a value, but we will deal with the steps one at a time. First, we need to find the value which is easy because
More informationFeatures and Requirements for an XML View Definition Language: Lessons from XML Information Mediation
Page 1 of 5 Features and Requirements for an XML View Definition Language: Lessons from XML Information Mediation 1. Introduction C. Baru, B. Ludäscher, Y. Papakonstantinou, P. Velikhov, V. Vianu XML indicates
More informationBinary Trees
Binary Trees 4-7-2005 Opening Discussion What did we talk about last class? Do you have any code to show? Do you have any questions about the assignment? What is a Tree? You are all familiar with what
More informationCSE 142/143 Unofficial Commenting Guide Eric Arendt, Alyssa Harding, Melissa Winstanley
CSE 142/143 Unofficial Commenting Guide Eric Arendt, Alyssa Harding, Melissa Winstanley In Brief: What You Need to Know to Comment Methods in CSE 143 Audience o A random person you don t know who wants
More informationTagSoup: A SAX parser in Java for nasty, ugly HTML. John Cowan
TagSoup: A SAX parser in Java for nasty, ugly HTML John Cowan (cowan@ccil.org) Copyright This presentation is: Copyright 2002 John Cowan Licensed under the GNU General Public License ABSOLUTELY WITHOUT
More informationThe Semi-Structured Data Model. csc343, Introduction to Databases Diane Horton originally based on slides by Jeff Ullman Fall 2017
The Semi-Structured Data Model csc343, Introduction to Databases Diane Horton originally based on slides by Jeff Ullman Fall 2017 Recap: Data models A data model is a notation for describing data, including:
More informationExtensible Markup Language (XML) Hamid Zarrabi-Zadeh Web Programming Fall 2013
Extensible Markup Language (XML) Hamid Zarrabi-Zadeh Web Programming Fall 2013 2 Outline Introduction XML Structure Document Type Definition (DTD) XHMTL Formatting XML CSS Formatting XSLT Transformations
More informationBeginning To Define ebxml Initial Draft
Beginning To Define ebxml Initial Draft File Name Version BeginningToDefineebXML 1 Abstract This document provides a visual representation of how the ebxml Architecture could work. As ebxml evolves, this
More informationOneNote vs. Evernote: A personal take on two great note-taking apps
REVIEW OneNote vs. Evernote: A personal take on two great note-taking apps Evernote and Microsoft OneNote have taken different approaches in their quest to be the best note-taking app. Here s where each
More informationRyan Marcotte CS 475 (Advanced Topics in Databases) March 14, 2011
Ryan Marcotte www.cs.uregina.ca/~marcottr CS 475 (Advanced Topics in Databases) March 14, 2011 Outline Introduction to XNF and motivation for its creation Analysis of XNF s link to BCNF Algorithm for converting
More informationIntro. Scheme Basics. scm> 5 5. scm>
Intro Let s take some time to talk about LISP. It stands for LISt Processing a way of coding using only lists! It sounds pretty radical, and it is. There are lots of cool things to know about LISP; if
More informationAzon Master Class. By Ryan Stevenson Guidebook #7 Site Construction 2/3
Azon Master Class By Ryan Stevenson https://ryanstevensonplugins.com/ Guidebook #7 Site Construction 2/3 Table of Contents 1. Creation of Site Pages 2. Category Pages Creation 3. Home Page Creation Creation
More informationBlaise Questionnaire Text Editor (Qtxt)
Blaise Questionnaire Text Editor (Qtxt) Grayson Mitchell, Statistics New Zealand 1. Abstract Qtxt is a program designed to reduce the amount of work involved with the production of large questionnaires.
More informationProgrammazione Web a.a. 2017/2018 HTML5
Programmazione Web a.a. 2017/2018 HTML5 PhD Ing.Antonino Raucea antonino.raucea@dieei.unict.it 1 Introduzione HTML HTML is the standard markup language for creating Web pages. HTML stands for Hyper Text
More informationA new generation of tools for SGML
Article A new generation of tools for SGML R. W. Matzen Oklahoma State University Department of Computer Science EMAIL rmatzen@acm.org Exceptions are used in many standard DTDs, including HTML, because
More informationThe Extensible Markup Language (XML) and Java technology are natural partners in helping developers exchange data and programs across the Internet.
1 2 3 The Extensible Markup Language (XML) and Java technology are natural partners in helping developers exchange data and programs across the Internet. That's because XML has emerged as the standard
More informationThree OPTIMIZING. Your System for Photoshop. Tuning for Performance
Three OPTIMIZING Your System for Photoshop Tuning for Performance 72 Power, Speed & Automation with Adobe Photoshop This chapter goes beyond speeding up how you can work faster in Photoshop to how to make
More informationWindows Script Host Fundamentals
O N E Windows Script Host Fundamentals 1 The Windows Script Host, or WSH for short, is one of the most powerful and useful parts of the Windows operating system. Strangely enough, it is also one of least
More informationCombinatorics Prof. Dr. L. Sunil Chandran Department of Computer Science and Automation Indian Institute of Science, Bangalore
Combinatorics Prof. Dr. L. Sunil Chandran Department of Computer Science and Automation Indian Institute of Science, Bangalore Lecture - 5 Elementary concepts and basic counting principles So, welcome
More informationWeb Evaluation Report Guidelines
Web Evaluation Report Guidelines Graduate Students: You are required to conduct a usability test for your final project in this course. Please review the project description and the evaluation rubric on
More informationIntroduction to XML. Large Scale Programming, 1DL410, autumn 2009 Cons T Åhs
Introduction to XML Large Scale Programming, 1DL410, autumn 2009 Cons T Åhs XML Input files, i.e., scene descriptions to our ray tracer are written in XML. What is XML? XML - extensible markup language
More informationJAVASCRIPT - CREATING A TOC
JAVASCRIPT - CREATING A TOC Problem specification - Adding a Table of Contents. The aim is to be able to show a complete novice to HTML, how to add a Table of Contents (TOC) to a page inside a pair of
More informationChris' Makefile Tutorial
Chris' Makefile Tutorial Chris Serson University of Victoria June 26, 2007 Contents: Chapter Page Introduction 2 1 The most basic of Makefiles 3 2 Syntax so far 5 3 Making Makefiles Modular 7 4 Multi-file
More informationRed-Black trees are usually described as obeying the following rules :
Red-Black Trees As we have seen, the ideal Binary Search Tree has height approximately equal to log n, where n is the number of values stored in the tree. Such a BST guarantees that the maximum time for
More informationJava EE 7: Back-end Server Application Development 4-2
Java EE 7: Back-end Server Application Development 4-2 XML describes data objects called XML documents that: Are composed of markup language for structuring the document data Support custom tags for data
More informationEBOOK THE BEGINNER S GUIDE TO DESIGN VERIFICATION AND DESIGN VALIDATION FOR MEDICAL DEVICES
EBOOK THE BEGINNER S GUIDE TO DESIGN VERIFICATION AND DESIGN VALIDATION FOR MEDICAL DEVICES JON SPEER, FOUNDER & VP OF QA/RA GREENLIGHT.GURU THE BEGINNER S GUIDE TO DESIGN VERIFICATION AND DESIGN VALIDATION
More informationIntroduction to XML. Chapter 133
Chapter 133 Introduction to XML A. Multiple choice questions: 1. Attributes in XML should be enclosed within. a. single quotes b. double quotes c. both a and b d. none of these c. both a and b 2. Which
More informationAnatomy of a Standard Transcript
Anatomy of a Standard Transcript Maddie: Hi everyone! Throughout this joint project, Eli, Christina, & I all had to use technical standards to make sure our products met the necessary requirements & specifications,
More informationRIS shading Series #2 Meet The Plugins
RIS shading Series #2 Meet The Plugins In this tutorial I will be going over what each type of plugin is, what their uses are, and the basic layout of each. By the end you should understand the three basic
More informationCS145 Introduction. About CS145 Relational Model, Schemas, SQL Semistructured Model, XML
CS145 Introduction About CS145 Relational Model, Schemas, SQL Semistructured Model, XML 1 Content of CS145 Design of databases. E/R model, relational model, semistructured model, XML, UML, ODL. Database
More informationRegular Expressions Explained
Found at: http://publish.ez.no/article/articleprint/11/ Regular Expressions Explained Author: Jan Borsodi Publishing date: 30.10.2000 18:02 This article will give you an introduction to the world of regular
More information1 of 5 5/11/2006 12:10 AM CS 61A Spring 2006 Midterm 2 solutions 1. Box and pointer. Note: Please draw actual boxes, as in the book and the lectures, not XX and X/ as in these ASCII-art solutions. Also,
More informationOne of the main selling points of a database engine is the ability to make declarative queries---like SQL---that specify what should be done while
1 One of the main selling points of a database engine is the ability to make declarative queries---like SQL---that specify what should be done while leaving the engine to choose the best way of fulfilling
More information1 Dynamic Memory continued: Memory Leaks
CS104: Data Structures and Object-Oriented Design (Fall 2013) September 3, 2013: Dynamic Memory, continued; A Refresher on Recursion Scribes: CS 104 Teaching Team Lecture Summary In this lecture, we continue
More informationTERMINOLOGY MANAGEMENT DURING TRANSLATION PROJECTS: PROFESSIONAL TESTIMONY
LINGUACULTURE, 1, 2010 TERMINOLOGY MANAGEMENT DURING TRANSLATION PROJECTS: PROFESSIONAL TESTIMONY Nancy Matis Abstract This article briefly presents an overview of the author's experience regarding the
More informationIntroduction to XML. Yanlei Diao UMass Amherst April 17, Slides Courtesy of Ramakrishnan & Gehrke, Dan Suciu, Zack Ives and Gerome Miklau.
Introduction to XML Yanlei Diao UMass Amherst April 17, 2008 Slides Courtesy of Ramakrishnan & Gehrke, Dan Suciu, Zack Ives and Gerome Miklau. 1 Structure in Data Representation Relational data is highly
More informationWeek 2: The Clojure Language. Background Basic structure A few of the most useful facilities. A modernized Lisp. An insider's opinion
Week 2: The Clojure Language Background Basic structure A few of the most useful facilities A modernized Lisp Review of Lisp's origins and development Why did Lisp need to be modernized? Relationship to
More informationThe Syntax of auto Declarations
2007-08-01 Daveed Vandevoorde daveed@edg.com 1 The Issues Two proposed new uses of the keyword auto (one of which is already in the Working Paper) are raising new parsing ambiguity issues. The issues arise
More informationClass #7 Guidebook Page Expansion. By Ryan Stevenson
Class #7 Guidebook Page Expansion By Ryan Stevenson Table of Contents 1. Class Purpose 2. Expansion Overview 3. Structure Changes 4. Traffic Funnel 5. Page Updates 6. Advertising Updates 7. Prepare for
More informationIntro. Speed V Growth
Intro Good code is two things. It's elegant, and it's fast. In other words, we got a need for speed. We want to find out what's fast, what's slow, and what we can optimize. First, we'll take a tour of
More informationThe Stack, Free Store, and Global Namespace
Pointers This tutorial is my attempt at clarifying pointers for anyone still confused about them. Pointers are notoriously hard to grasp, so I thought I'd take a shot at explaining them. The more information
More informationEmbedding Python in Your C Programs
1 of 7 6/18/2006 9:05 PM Embedding Python in Your C Programs William Nagel Abstract C, meet Python. Python, this is C. With surprisingly little effort, the Python interpreter can be integrated into your
More informationXML (Extensible Markup Language)
Basics of XML: What is XML? XML (Extensible Markup Language) XML stands for Extensible Markup Language XML was designed to carry data, not to display data XML tags are not predefined. You must define your
More informationSTORAGE AREA NETWORK ESSENTIALS: A COMPLETE GUIDE TO UNDERSTANDING AND IMPLEMENTING SANS BY RICHARD BARKER, PAUL MASSIGLIA
STORAGE AREA NETWORK ESSENTIALS: A COMPLETE GUIDE TO UNDERSTANDING AND IMPLEMENTING SANS BY RICHARD BARKER, PAUL MASSIGLIA DOWNLOAD EBOOK : STORAGE AREA NETWORK ESSENTIALS: A COMPLETE GUIDE TO UNDERSTANDING
More informationXML in Databases. Albrecht Schmidt. al. Albrecht Schmidt, Aalborg University 1
XML in Databases Albrecht Schmidt al@cs.auc.dk http://www.cs.auc.dk/ al Albrecht Schmidt, Aalborg University 1 What is XML? (1) Where is the Life we have lost in living? Where is the wisdom we have lost
More informationXML. Document Type Definitions. Database Systems and Concepts, CSCI 3030U, UOIT, Course Instructor: Jarek Szlichta
XML Document Type Definitions 1 XML XML stands for extensible Markup Language. XML was designed to describe data. XML has come into common use for the interchange of data over the Internet. 2 Well-Formed
More informationFormal Methods of Software Design, Eric Hehner, segment 1 page 1 out of 5
Formal Methods of Software Design, Eric Hehner, segment 1 page 1 out of 5 [talking head] Formal Methods of Software Engineering means the use of mathematics as an aid to writing programs. Before we can
More informationExcel Basics Rice Digital Media Commons Guide Written for Microsoft Excel 2010 Windows Edition by Eric Miller
Excel Basics Rice Digital Media Commons Guide Written for Microsoft Excel 2010 Windows Edition by Eric Miller Table of Contents Introduction!... 1 Part 1: Entering Data!... 2 1.a: Typing!... 2 1.b: Editing
More informationCSCI 204 Introduction to Computer Science II. Lab 6: Stack ADT
CSCI 204 Introduction to Computer Science II 1. Objectives In this lab, you will practice the following: Learn about the Stack ADT Implement the Stack ADT using an array Lab 6: Stack ADT Use a Stack to
More informationDiagnosing Java code: Designing extensible applications, Part 3
Diagnosing Java code: Designing extensible applications, Part 3 Examine when, where, and how black box extensibility works best Level: Introductory Eric Allen (eallen@cs.rice.edu), Ph.D. candidate, Java
More informationThey are a block of code plus the bindings to the environment they came from (Ragusa Idiom / function object).
maxbox Starter 31 Start with Closures 1.1 A Function Block in a Box Today we step through a topic of closures. One of the questions that comes up when learning closures is how they can be useful when they're
More informationIt Might Be Valid, But It's Still Wrong Paul Maskens and Andy Kramek
Seite 1 von 5 Issue Date: FoxTalk July 2000 It Might Be Valid, But It's Still Wrong Paul Maskens and Andy Kramek This month, Paul Maskens and Andy Kramek discuss the problems of validating data entry.
More informationAssignment #1: /Survey and Karel the Robot Karel problems due: 1:30pm on Friday, October 7th
Mehran Sahami Handout #7 CS 06A September 8, 06 Assignment #: Email/Survey and Karel the Robot Karel problems due: :0pm on Friday, October 7th Email and online survey due: :9pm on Sunday, October 9th Part
More informationHTML. Mohammed Alhessi M.Sc. Geomatics Engineering. Internet GIS Technologies كلية اآلداب - قسم الجغرافيا نظم المعلومات الجغرافية
HTML Mohammed Alhessi M.Sc. Geomatics Engineering Wednesday, February 18, 2015 Eng. Mohammed Alhessi 1 W3Schools Main Reference: http://www.w3schools.com/ 2 What is HTML? HTML is a markup language for
More informationRescuing Lost Files from CDs and DVDs
Rescuing Lost Files from CDs and DVDs R 200 / 1 Damaged CD? No Problem Let this Clever Software Recover Your Files! CDs and DVDs are among the most reliable types of computer disk to use for storing your
More informationWhy are there so many programming languages? Why do we have programming languages? What is a language for? What makes a language successful?
Chapter 1 :: Introduction Introduction Programming Language Pragmatics Michael L. Scott Why are there so many programming languages? evolution -- we've learned better ways of doing things over time socio-economic
More information/633 Introduction to Algorithms Lecturer: Michael Dinitz Topic: Priority Queues / Heaps Date: 9/27/17
01.433/33 Introduction to Algorithms Lecturer: Michael Dinitz Topic: Priority Queues / Heaps Date: 9/2/1.1 Introduction In this lecture we ll talk about a useful abstraction, priority queues, which are
More informationTracking changes in Word 2007 Table of Contents
Tracking changes in Word 2007 Table of Contents TRACK CHANGES: OVERVIEW... 2 UNDERSTANDING THE TRACK CHANGES FEATURE... 2 HOW DID THOSE TRACKED CHANGES AND COMMENTS GET THERE?... 2 WHY MICROSOFT OFFICE
More informationIntroduction to XML. An Example XML Document. The following is a very simple XML document.
Introduction to XML Extensible Markup Language (XML) was standardized in 1998 after 2 years of work. However, it developed out of SGML (Standard Generalized Markup Language), a product of the 1970s and
More informationMehran Sahami Handout #7 CS 106A September 24, 2014
Mehran Sahami Handout #7 CS 06A September, 0 Assignment #: Email/Survey and Karel the Robot Karel problems due: :pm on Friday, October rd Email and online survey due: :9pm on Sunday, October th Part I
More informationWhy You Should Not Use Arch
Why You Should Not Use Arch A new users guide to highly personalized, low maintenance operating system. Artur Frącek CC BY-NC-ND 4.0 1 Intro Arch is a very good Linux distribution so it is not a surprise
More informationmarkup language carry data define your own tags self-descriptive W3C Recommendation
XML intro What is XML? XML stands for EXtensible Markup Language XML is a markup language much like HTML XML was designed to carry data, not to display data XML tags are not predefined. You must define
More informationEvaluation Guide for ASP.NET Web CMS and Experience Platforms
Evaluation Guide for ASP.NET Web CMS and Experience Platforms CONTENTS Introduction....................... 1 4 Key Differences...2 Architecture:...2 Development Model...3 Content:...4 Database:...4 Bonus:
More informationThe XML Metalanguage
The XML Metalanguage Mika Raento mika.raento@cs.helsinki.fi University of Helsinki Department of Computer Science Mika Raento The XML Metalanguage p.1/442 2003-09-15 Preliminaries Mika Raento The XML Metalanguage
More informationOverview. Structured Data. The Structure of Data. Semi-Structured Data Introduction to XML Querying XML Documents. CMPUT 391: XML and Querying XML
Database Management Systems Winter 2004 CMPUT 391: XML and Querying XML Lecture 12 Overview Semi-Structured Data Introduction to XML Querying XML Documents Dr. Osmar R. Zaïane University of Alberta Chapter
More information