What is the Data Model?The set of activities and techniques that enable us to capture the structure and operations of an organization, as well as the proposed information solution that will enable the organization to achieve its goals.It is an abstract model that documents and organizes the business data for communication between functional and technical people. Why we need Data Model?To better understand the requirementsIt helps to build a robust designProvide consistency across ProjectsHelps developers to find the issues and redesign in case changes in the functionalityImproves the data quality and helps to analyse the requirements for their dataHelp to distribute the data across their productHelps in reducing the data maintenance like where and how the data is stored and gives a clear picture of the flow of dataCan be used to reuse to create a similar productHelps in improving the performanceWhat are the types of data modeling?Business Process Modeling (BPM)Object-Oriented Modeling (OOM-UML)Conceptual Data Modeling (CDM-E/R)Physical Data Modeling (PDM)

Designing Levels of Data Models or Development Life Cycle-Business Model ( Abstract level)-Enterprise Model (Objects and Properties)-Conceptual (Entities, Attributes, Relations)- Logical (Tables, Columns, PKs, FKs)-Physical (Tables, Crud Operations, Indexes, Partitioning) (Detail Level)

How can u create a data model with the existing Database or a product?-Reverse EngineeringWho all will be benefited from the data model?-Project ManagersProject Scope Management (Enterprise Data Model) Project Quality Management-Business Analyst/ SpecialistRequirement Analysis-Architects Solution Design Database Design-DevelopersGenerate SQL/DDL from the ModelBride between technical and functional areaData Migration -DBAs Performance ImprovementsWhen should we create a data model?Design level or at the level of conceptual data model (Its a prerequisite for design)During the analysis and design comes the conceptual data model and when the conceptual is completed it is delivered to developers comes the physical design.Requirement-analysis-design-develop-deploy-monitor and maintain-requirementOnce the design is done and deliverable design provided to the developers is a physical design Who will actually involve in creating a Data model?Data base modeller, Database designer, DBA

What is Conceptual Data Model?Identifies the highest level of relationships between different entities without specifying any attributes.Logical Data ModelDetail each entities with attributesSometimes combines the conceptual and logical modelPrimary keys for each entity is specifiedForeign Keys are specifiedNormalize the dataPhysical Data modelRepresents how the model will be built in the databaseShows tables structures, columns, column data type, constraints, primary key, foreign keyAnd relation between tablesDe-normalization may occur according our requirementPhysical model may vary for different RDBMS

FeatureConceptualLogicalPhysical

Entity Names

Entity Relationships

Attributes

Primary Keys

Foreign Keys

Table Names

Column Names

Column Data Types

Tools1. Microsoft Visio2. Power designer

Entities must not be multiplied beyond necessity

What is a Business Model (Abstract level/Context)?

High Level Abstract model of the business Identify the global things of significance Identify the key data Environment Model