PATTERNS OF DATA MODELING- P34 potx

... acquisitions that cause databases to be merged. For example, the merger of Delta Airlines and Northwest Airlines created a need to merge frequent flyer databases. The tricky part of merging data is determining ... entities remain in the database. Gradually migrate data to the active entity. • Eventually con- solidates the data. • There is less risk of stale references as obso...

Ngày tải lên: 05/07/2014, 06:20

... 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 Transac- tions on Database ... Vlissides. Design Patterns: El- ements of Reusable Object-Oriented Software. Boston, Massachusetts: Addison-Wesley, 1995. [Hay-1996] David C. Hay. Data Model Patterns: Conventions...

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... 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 tem- plate. A Node is either ... 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.)...

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... 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 Figure 2.36 Tree changing ... differ from that of its various positions. 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 da...

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... (directed graph) is a set of nodes and a set of directed edges that connect nodes. (Note: in a directed graph all nodes do not have to be connected.) You need not show DG in a use of the template. A ... represented via the coupling between nodes. The populated tables use different data than Figure 3.1 because the premise of the template is a tree that is generalized to having multip...

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... 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 ... Item description: UML template. Use when the same model relates data and metadata. ItemDescription Item Characterization Metadata Data Flexibility General purpose Specific Volatility...

Ngày tải lên: 05/07/2014, 06:20

... relational database tables for the equipment example at the start of the chapter (Figure 14.2). Figure 14.13 Diagram type subject area: UML model. The kind of model construct determines the kind of ... Area Figure 14.13 and Figure 14.14 determine the kind of diagram construct from the Diagram- Type and kind of model construct. For example, the combination of a DiagramType and an...

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... unified view of data. ACM Transac- tions on Database Systems 1, 1 (March 1976). [Hoberman-2010] Steve Hoberman. Data Modeling Made Simple: A Practical Guide for Business and IT Professionals, ... Explanation of the IDEF1X Notation The IDEF1X literature often uses the term “cardinality” incorrectly, instead of the prop- er term “multiplicity.” Multiplicity is a constraint on the size...

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Ngày tải lên: 05/07/2014, 06:20

... Modeling Notation 1 1.3 What Is a Pattern? 2 1.4 Why Are Patterns Important? 3 1.5 Drawbacks of Patterns 4 1.6 Pattern vs. Seed Model 4 1.7 Aspects of Pattern Technology 5 1.8 Chapter Summary 6 Bibliographic ... Summary 89 Bibliographic Notes 89 References 90 Chapter 7 Summary of Templates 91 Part II: Antipatterns 95 Chapter 8 Universal Antipatterns 97 8.1 Symmetric Relationship Ant...

Ngày tải lên: 05/07/2014, 06:20