fundamentals of data modeling

... controlling data redundancy to enhancing communications with users By meeting each of these challenges through good database design, you improve the performance of your database Overview of Data Modeling ... definition of an FK is that it refers to a PK or UK Overview of Data Modeling and Database Design 8Ć27 8Ć28 Introduction to Oracle: SQL and PL/SQL Using Procedure Builder Designing the Database The database ... refine the system Overview of Data Modeling and Database Design 8Ć7 8Ć8 Introduction to Oracle: SQL and PL/SQL Using Procedure Builder Database Design Designing a relational database system involves...

Ngày tải lên: 10/12/2013, 17:15

... controlling data redundancy to enhancing communications with users By meeting each of these challenges through good database design, you improve the performance of your database Overview of Data Modeling ... design Database Design Database design is just one of the stages of the development cycle Through good database design, you can achieve a reliable, high-performance system Challenges to Managing Data ... into a relational database design Overview of Data Modeling and Database Design 8Ć3 8Ć4 Introduction to Oracle: SQL and PL/SQL Using Procedure Builder Overview When you create a database, you need...

Ngày tải lên: 21/12/2013, 06:17

... PATTERNS OF DATA MODELING EMERGING DIRECTIONS IN DATABASE SYSTEMS AND APPLICATIONS Series Editor Sham Navathe Professor Georgia Institute of Technology College of Computing Atlanta, ... Computing Atlanta, Georgia, U.S.A Patterns of Data Modeling, Michael Blaha Forthcoming Publications Advanced Data Management, Edward Omiecinski Bioinformatics Database Systems, Jason T.L Wang and Katherine ... for Automated Physical Database Design, Nicolas Bruno and Surajit Chaudhuri PATTERNS OF DATA MODELING MICHAEL BLAHA Boca Raton London New York CRC Press is an imprint of the Taylor & Francis...

Ngày tải lên: 05/07/2014, 06:20

... Introduction 1.1 What Is a Model? 1.2 Modeling Notation 1.3 What Is a Pattern? 1.4 Why Are Patterns Important? 1.5 Drawbacks of Patterns 1.6 Pattern vs Seed Model 1.7 Aspects of Pattern Technology 1.8 Chapter ... Chapter Summary Bibliographic Notes References Chapter 9.1 9.2 9.3 9.4 9.5 Non -Data- Warehouse Antipatterns Derived Data Antipattern Parallel Attributes Antipattern Parallel Relationships Antipattern ... Chapter Summary Bibliographic Notes References Chapter 13 Softcoded Values 13.1 UML Model 13.2 IDEF1X Model 13.3 Architecture 13.4 Softcoding Variations 13.5 Chapter Summary Bibliographic Notes...

Ngày tải lên: 05/07/2014, 06:20

... expertly building data models This book focuses on databases and not on programming, because most commercial software is built around a database The database representation (the data model) sets ... for this book I have been modeling application and enterprise data for 25 years now—the last 15 as a consultant to dozens of organizations I’m often asked how I conceive software models, and why ... scope, and set the xiii xiv Preface key abstractions in the software These tasks revolve around models and often data models The skillful use of patterns is intrinsic to building quality models • Enterprise...

Ngày tải lên: 05/07/2014, 06:20

... and add database details From IDEF1X I generate database code The UML is good for abstract modeling and not for database design IDEF1X is good for database design and not for abstract modeling ... Enriched modeling language Patterns extend a modeling language—you need not think only in terms of primitives; you can also think in terms of frequent combinations Patterns provide a higher level of ... out of the heads of experts and explicitly represent them Development decisions and rationale are made apparent • Reduce modeling difficulty Many developers find modeling difficult because of...

Ngày tải lên: 05/07/2014, 06:20

... Pattern-Oriented Software Architecture: A System of Patterns Chichester, United Kingdom: Wiley, 1996 [Chen-1976] PPS Chen The entity-relationship model—toward a unified view of data ACM Transactions on Database ... Vlissides Design Patterns: Elements of Reusable Object-Oriented Software Boston, Massachusetts: Addison-Wesley, 1995 [Hay-1996] David C Hay Data Model Patterns: Conventions of Thought New York, New York: ... Michael J Hernandez Database Design for Mere Mortals: A Hands-On Guide to Relational Database Design (2nd Edition) Boston: Addison-Wesley, 2003 [Hoberman-2009] Steve Hoberman Data Modeling Made Simple,...

Ngày tải lên: 05/07/2014, 06:20

... practice there can be any number of levels The angle brackets denote parameters that require substitution A Tree is a hierarchy of entities with the entities of each level having the same entity ... enforce the sequence of types in the levels of the hierarchy The hardcoded representation is easy to understand, but it is fragile The hardcoded template is only appropriate when the data structure ... known and unlikely to change Otherwise a change to the hierarchy of types breaks the model and database structure necessitating rework of application code In practice I seldom build applications with...

Ngày tải lên: 05/07/2014, 06:20

... 1.1.2, and 1.2.1 The nesting can be arbitrarily deep depending on the desired level of detail The RFP yields a tree of requirements 2.3 Structured Tree Template 19 RFP Requirement {Every requirement ... from branch nodes A Tree is a hierarchy of nodes and has one node as the root A particular node may, or may not, be the root You need not show Tree in a use of the template root child ... nodes each of which, in turn, can be a leaf node or a further branch node Figure 2.18 adds the constraint that a tree cannot have any cycles (See Section 2.2.1 for an explanation of cycles.)...

Ngày tải lên: 05/07/2014, 06:20

... Overlapping trees occur less often than structured and simple trees Mechanical parts provide a compelling example In Figure 2.32 a PartRole can be the root of a BOM (bill -of- material) and have multiple ... multiple trees A Tree is a hierarchy of nodes and has one node as the root A Node is an entity type whose records are organized as a Tree A node may be the root of multiple trees You should include ... with a tree record and retrieving the node that is the root of the tree Traverse the parent relationship to retrieve the collection of children for the root node You can recursively expand the...

Ngày tải lên: 05/07/2014, 06:20

... time A Tree is a hierarchy of nodes and has one node as the root A Node is a position within a Tree An Entity is something with identity and data A Binding is the coupling of an Entity to a Node ... node name could also be invariant over time (candidate key of nodeName alone) Note that the handling of time reflects a limitation of relational DBMSs It would be better to use time intervals ... Thus a person can be manager of one group and an acting manager of another group The same person may be an individual contributor and a manager during different portions of a 30 Chapter / Tree Template...

Ngày tải lên: 05/07/2014, 06:20

... over time Records the history of a tree This template permits storing of the past, present, and future content of trees • Degenerate node and edge Use when there is data for the parent–child grouping ... different entity type and the sequence of entity types is well known and unlikely to change • Simple tree Suffices when tree decomposition is merely a matter of data structure and all nodes are the ... Excerpt of data model for calendar application • Structured tree Use when branch nodes differ from leaf nodes For example, the command dir directoryFileName elicits a different response from dir dataFileName...

Ngày tải lên: 05/07/2014, 06:20

... multiple files, some or all of which may be subdirectories The combination of a DirectoryFile and a fileName yields a specific File—file names are unique within the context of a directory All Files ... (directed graph) is a set of nodes and a set of directed edges that connect nodes (Note: in a directed graph all nodes not have to be connected.) You need not show DG in a use of the template A Node ... file graph must be acyclic.} fileName DataFile DirectoryFile Figure 3.15 Structured directed graph: File system directory model In Figure 3.15 a File may be a DataFile or a DirectoryFile Directories...

Ngày tải lên: 05/07/2014, 06:20

... published description of air travel between two airports The frequency indicates the days of the week for which the PublishedFlight applies A PublishedFlight consists of a sequence of PublishedFlightLegs ... is important to store data about the connection itself A DG (directed graph) is a set of nodes and a set of directed edges that connect nodes You need not show DG in a use of the template A Node ... Tables Figure 3.23 and Figure 3.24 show node and edge directed graph tables populated with data The values of the IDs are arbitrary, but internally consistent A c B e d f D C h g F Node table node...

Ngày tải lên: 05/07/2014, 06:20

... node name could also be invariant over time (candidate key of nodeName alone) Note that the handling of time reflects a limitation of relational DBMSs It would be better to use time intervals ... when edges are unimportant and history must be recorded A DG (directed graph) is a set of nodes and a set of directed edges that connect nodes (Note: in a directed graph all the nodes not have ... Changing over Time Template 53 in a use of the template A Node is a position within a directed graph The distinction between parent and child causes the sense of direction that effects directed edges...

Ngày tải lên: 05/07/2014, 06:20

... unimportant and the history of a directed graph must be recorded • Node and edge directed graph changing over time Use when there is data for edges and the history of a directed graph must be ... Sample Populated Tables Figure 3.46 shows tables populated with data for the node and edge directed graph changing over time The values of the IDs are arbitrary, but internally consistent A null effectiveDate ... graphs occur in many application models and are often a critical issue for representation There are six templates for directed graphs with different trade-offs • Simple directed graph Suffices when...

Ngày tải lên: 05/07/2014, 06:20

... Bibliographic Notes Page 89 of [Hay-1996] has an example of projects that involve the node and edge directed graph References [Hay-1996] David C Hay Data Model Patterns: Conventions of Thought New York, ... An undirected graph is a set of nodes and a set of edges Each edge connects two nodes (which may be the same) The nodes of an undirected graph can have any number of edges Undirected graphs arise ... (undirected graph) is a set of nodes and a set of edges that connect nodes (Note: in an undirected graph all nodes not have to be connected.) You need not show UDG in a use of the template A Node...

Ngày tải lên: 05/07/2014, 06:20

... Tables Figure 4.12 and Figure 4.13 show connection undirected graph tables populated with data The values of the IDs are arbitrary, but internally consistent 68 Chapter / Undirected Graph Template ... variety of equipment that is connected by piping For stress calculations, all that matters is that the equipment is connected Stress calculations ensure that piping does not break under the load of ... cannot handle edges that connect twice to the same node A UDG (undirected graph) is a set of nodes and a set of edges that connect nodes (Note: in an undirected graph all the nodes need not be connected.)...

Ngày tải lên: 05/07/2014, 06:20

... UML template Use when the same model relates data and metadata Table 5.1 Comparison of Item (data) and ItemDescription (metadata) ItemDescription Metadata General purpose Changes slowly Requires ... background for data and a light gray for metadata The item description template is useful if you cannot fully describe data as software is being developed The template lets you enter data and its ... more typical approach of defining data structure at compile time Table 5.1 compares Item and ItemDescription 74 5.1 Item Description Template 75 Metadata Data * Figure...

Ngày tải lên: 05/07/2014, 06:20

... convention differentiates metadata from data Light gray indicates metadata and white indicates data * * Metadata * Data * ... should be treated as data or metadata Figure 5.8 shows another example, relating report definition to report execution ReportDefinition * name Metadata creator Person name * Data ReportExecution ... illustrates that there can be multiple levels of item description LibraryItemType is metadata with regard to LibraryItem And LibraryItem is metadata with regard to LibraryItemCopy Thus Figure...

Ngày tải lên: 05/07/2014, 06:20