DBMS-Week-4B-ER-UML-Modeling-1 - WEEK 4B SHAILESH AGARWAL...

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WEEK4B SHAILESHAGARWAL, PH.D. 1
Review of last class Relational Database Design Functional Dependencies Relational Design Anomalies Normal Forms Converting to Normal Forms 2
Agenda Data Modeling Entity Relationship Model Unified Modeling Language Modeling Temporal Data Class Exercises 3
Database Schema Design Database schema specifies Tables, Columns Constraints Indexes Triggers Database schema design driven by “Types” of data that need to be stored Volume and Velocity of data being collected Rate of change of this data Kinds and frequency of queries Frequency of database updates Data Model Business rules and constraints for this data 4
Data Modeling A Data Model provides a framework for representing and understanding entities, their data, business rules & constraints in a given context A context includes a Domain and one or more Applications Domain / Applications Corporation Sales, HR, Marketing Automation, Finance…University Student Management, Course Mgmt, Facilities Hospital Patient Records, Compliance, Nursing Mgmt Government DMV, Sales Tax, Immigration, Federal Aid Data models can be represented at different levels such as: Conceptual, Logical or Physical model 5
Data Model Levels ConceptualUnderstand entities and their relationships at a high level LogicalUnderstand details about these entities such as attributes and relationship cardinalities without worrying about implementation PhysicalDefine DBMS specific implementation including table definitions, column types, indexes etc Such partitioning also enables individuals with different levels of expertise to contribute effectively at different levels 6
Modeling Frameworks Entity Relationship Model (E/R) Classic Modeling Framework Unified Modeling Language (UML) State of the art Both frameworks are graphical Both can be semi-automatically translated to a relational model Each framework has their own notation But, they are reasonably similar 7
Entity Relationship Model 8 CUSTOMER ORDER ORDER_ITEM INVENTORY
Entity Relationship Model 9 CUSTOMER CUSTOMER ID NAME PHONE DATE REGISTERED ORDER ORDER ID ORDER DATE DELIVERY DATE STATUS ORDER_ITEM ORDER ITEM ID QTY ORDERED QTY DELIVERED INVENTORY INVENTORY ID DESCRIPTION QTY AVAILABLE STATUS 1:1 0:*1:1 0:*1:1 0:*
E/R Modeling Concepts Entity / Entity Set Attribute Relationship 10
Entity Set An Entityis meant to represent a person, place, thing or even a concept relevant to the application domain Entities of the same type are referred to as an Entity Set CUSTOMERentity set represents customers of a business ORDERrepresents orders that customers are placing INVENTORYrepresents product items that are being ordered 11
Attribute Need a mechanism to capture important and relevant information about each entity An Entity is modeled with properties

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