Data Modeling Essentials 2005 phần 8 pps
Data Modeling Essentials 2005 phần 8 pps
... are limited in their ability to accommodate update transactions. 12 .8 Summary ■ 387 Simsion-Witt_12 10/11/04 8: 58 PM Page 387 Surgeon Physician Prescribing Practice Drug Disease Component Component- Component Structure Procedure Pension Scheme Pension Benefit Eligibility Benefit Employee Class (a) Note: ... the second-level organization units that belong to it). 380 ■ Chapter 12 Phy...
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Data Modeling Essentials 2005 phần 1 ppsx
... format. 4 ■ Chapter 1 What Is Data Modeling? Figure 1.1 An information system. Report Program DATABASE Program data Report Program data data ProgramProgram data data 1 Data models can be presented ... UML 222 7.5 Object Role Modeling 227 7.6 Summary 2 28 Part II Putting It Together 229 Chapter 8 Organizing the Data Modeling Task 231 8. 1 Data Modeling in the Real Wor...
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Data Modeling Essentials 2005 phần 3 ppsx
... ID, Qualification Name, Qualification Date}) Simsion-Witt_03 10 /8/ 04 8: 02 PM Page 88 4.12 Benefits of Using Subtypes and Supertypes ■ 131 Figure 4 .8 Different views of a model. Permanent Employee Manager Professional Clerical Employee Contract Casual ... be stable 23 98 ■ Chapter 3 The Entity-Relationship Approach 23 The importance of stability for primary keys is discussed in Secti...
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Data Modeling Essentials 2005 phần 4 ppsx
... Identity Simsion-Witt_06 10/11/04 8: 57 PM Page 184 datatype requires the number of digits after the decimal point to be spec- ified. If the decimal datatype is not available, the integer datatype must be used. ... 10 /8/ 04 7:56 PM Page 152 5.4.4 Column Datatype and Length Requirements We now look at the translation of attribute types into column datatypes. If your DBMS does not support UD...
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Data Modeling Essentials 2005 phần 9 ppsx
... of History, 19 68 15.1 The Problem Few areas of data modeling are the subject of as much confusion as the handling of time-related and time-dependent data. Perhaps we are modeling data for an insurance ... and $80 ,000), which may or may not be recorded as data in the database itself. We discuss data that supports process rules in Section 14.5.7. Another example of a process r...
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Data Modeling Essentials 2005 phần 2 potx
... involved if changes to the logical data model are contemplated. In developing a system, data modeling and process modeling usually proceed broadly in parallel. Data modeling principles remain important ... of data. In Chapter 7 we look at some extensions to the basic conventions and some alternative modeling languages. 1.15 Summary Data and databases are central to informati...
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Data Modeling Essentials 2005 phần 5 pot
... to the data model: ■ Add the supertype. ■ Mark each of the original entity classes as a subtype of that supertype. 242 ■ Chapter 8 Organizing the Data Modeling Task Simsion-Witt_ 08 10 /8/ 04 7:46 ... Bulwer-Lytton 8. 1 Data Modeling in the Real World In the preceding chapters, we have focused largely on learning the lan- guage of data modeling without giving much attention...
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Data Modeling Essentials 2005 phần 6 pdf
... we use for selecting good 276 ■ Chapter 10 Conceptual Data Modeling Simsion-Witt_10 10/11/04 8: 49 PM Page 276 Chapter 10 Conceptual Data Modeling “Our job is to give the client not what he wants, ... “top down.” We look at these in the following sections. 284 ■ Chapter 10 Conceptual Data Modeling Simsion-Witt_10 10/11/04 8: 49 PM Page 284 sake of nonredundancy) that each non...
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Data Modeling Essentials 2005 phần 7 potx
... combina- tion of < ;Data Item 1 Name>, < ;Data Item 2 Name>, . . . and < ;Data Item n Name>.” 10. 18 The Assertions Approach ■ 317 Simsion-Witt_10 10/11/04 8: 49 PM Page 317 10. 18. 2.3. Attribute ... implement only its subtypes, Individual and 3 28 ■ Chapter 11 Logical Database Design 8 ANSI/ISO/IEC 9075. Simsion-Witt_11 10/11/04 8: 51 PM Page 3 28 rather than all of...
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Data Modeling Essentials 2005 phần 10 ppt
... for exampleyet we manage to get the job done! 488 ■ Chapter 16 Modeling for Data Warehouses and Data Marts Simsion-Witt_16 10 /8/ 04 8: 08 PM Page 488 Data warehouse design is particularly influenced ... consistent results. 4 78 ■ Chapter 16 Modeling for Data Warehouses and Data Marts Simsion-Witt_16 10 /8/ 04 8: 08 PM Page 4 78 Chapter 17 Enterprise Data Models and...
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