MARATHON CLASSEdi Purnomo PutraLecture Code : D5386

Normalisasi• Tujuan Normalisasi• Update anomalisinsert, update, delete• Functional dependency• Full functional dependency

nilainim, KdMtk• Partial dependency

namabarangidbarang

Normalisasinormalisasi adalah suatu teknik Formal Dalam Menentukan atribut dan menghasilkan kumpulan relasi yang bertujuan untuk menyediakan kebutuhan data yang diperlukan oleh perusahaan

• A technique for producting a set of relation with desirable properties, given data reqruirements of an enterprise

Tujuan Normalisasi1) Menjamin struktur data yang konsisten.2) Kerangkapan data yang minimal.3) Stabilitas struktur data yang maksimal

1)  Meminimalkan Jumlah Kapasitas Penyimpanan Yang Diperlukan Untuk menyimpan data.2) Meminimalkan resiko data yang tidak konsisten dalam suatu basis data.3) Meminimalkan kemungkinan update dan delete anomaly.4) Memaksimalkan stabilitas dari struktur data

Manfaat Normalisasi

Datawarehouse• Karakteristik DWH• ETL(Extract, transform, loading)• Datamart vs DWH

Karakteristik • Subject oriented

Customer, product, sales• Integrated

Data konsistenMale, M, Ma Male

• NonvolatileTidak bisa diubah refresh scd(Slow Changing Dimension)

• Time variantMingguna, bulanan, tahunandimensi waktu

ETL • Extract

Ekstract data dari ODS /OLTP(OPERASIONAL DATA SOURCE)• Transform

Penyamaan data JL, jalan, JLN JLMelakukan kalkulasi aggregate

• LoadMasukan data ke DWH/Data Mart

Datamart VS DWH• Data mart• 1 subject• Bagian dari data warehouse• Relative Sebentar• DWH• Beberapa subject• Implementasi waktu lama

ER• Fan trap• Chasm trap• Participant disjoint• Strong entity • Weak entity• Degree relation• Recursive• Single value atribute• Multivalue attribute

Prticiapant Disjoint• ParticipantAnd / or• Join disjoin Optional and mandatory

Participant Disjoint

Participant Disjoint

Optional OR

Mandatory Or

Degree

Degree of a RelationshipNumber of participating entities in relationship.

Relationship of degree :two is binary three is ternaryfour is quaternary.

Binary relationship called POwns

Ternary relationship called Registers

Quaternary relationship called Arranges

Recursive relationship called Supervises with role names

Attributes

• Attribute– Property of an entity or a relationship type.

• Attribute Domain– Set of allowable values for one or more

attributes.

Attributes

• Simple Attribute– Attribute composed of a single component

with an independent existence.

• Composite Attribute– Attribute composed of multiple components,

each with an independent existence.

Attributes

• Single-valued Attribute– Attribute that holds a single value for each

occurrence of an entity type.

• Multi-valued Attribute– Attribute that holds multiple values for each

occurrence of an entity type.

Attributes

• Derived Attribute– Attribute that represents a value that is

derivable from value of a related attribute, or set of attributes, not necessarily in the same entity type.

Entity Type

• Strong Entity Type– Entity type that is not existence-dependent

on some other entity type.

• Weak Entity Type– Entity type that is existence-dependent on

some other entity type.

• Fan Trap– Where a model represents a relationship

between entity types, but pathway between certain entity occurrences is ambiguous.

• Chasm Trap– Where a model suggests the existence of a

relationship between entity types, but pathway does not exist between certain entity occurrences.

Trap

An Example of a Fan Trap

Semantic Net of ER Model with Fan Trap

• At which branch office does staff number SG37 work?

Restructuring ER model to remove Fan Trap

Semantic Net of Restructured ER Model with Fan Trap Removed

• SG37 works at branch B003.

An Example of a Chasm Trap

Semantic Net of ER Model with Chasm Trap

• At which branch office is property PA14 available? Mengawasi, mengatur

ER Model restructured to remove Chasm Trap

Semantic Net of Restructured ER Model with Chasm Trap Removed

Key Type• Primary key NIM, KDMataKuliah• Composite key KdMatakuliah+NIM• Foreign key • Candidate key• Alternate key

Aggregate• Sum• Avg• Min• Max• Count

Intersect, except,union