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1 1 Pertemuan > > Matakuliah: >/ > Tahun: > Versi: >

2 2 Learning Outcomes Pada akhir pertemuan ini, diharapkan mahasiswa akan mampu : Problem pada E-R diagram :Fan TrapChasm TrapKasus E-R diagram sebuah organisasi

3 3 Outline Materi Problem pada E-R diagram : Fan Trap Chasm Trap Kasus E-R diagram sebuah organisasi

4 4 Chapter 11 (lanjutan pert 20) Entity-Relationship Modeling Transparencies

5 5 Problems with ER Models u Problems may arise when designing a conceptual data model called connection traps. u Often due to a misinterpretation of the meaning of certain relationships. u Two main types of connection traps are called fan traps and chasm traps.

6 6 Problems with ER Models u Fan Trap –Where a model represents a relationship between entity types, but pathway between certain entity occurrences is ambiguous. u Chasm Trap –Where a model suggests the existence of a relationship between entity types, but pathway does not exist between certain entity occurrences.

7 7 An Example of a Fan Trap

8 8 Semantic Net of ER Model with Fan Trap u At which branch office does staff number SG37 work?

9 9 Restructuring ER Model to Remove Fan Trap

10 10 Semantic Net of Restructured ER Model with Fan Trap Removed u SG37 works at branch B003.

11 11 An Example of a Chasm Trap

12 12 Semantic Net of ER Model with Chasm Trap u At which branch office is property PA14 available?

13 13 ER Model Restructured to Remove Chasm Trap

14 14 Semantic Net of Restructured ER Model with Chasm Trap Removed

15 15 > Selanjutnya pert 22 PERLUASAN E-R