Data Modeling Interview Question and Answer Videos

Video Tutorial 1: What is a Data Model and Data Modeler Responsibilities? What’s in it: Data Model, High Level Data Modeler Responsibilities along with images of a conceptual data model, logical data model and physical Data Model is explained using Erwin Data Modeling Tool. Video Tutorial 2: Explain Data Modeling Development Life Cycle? What’s in…

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What is Entity Relationship Diagram (ER Diagram) or ERD?

Entity Relationship Diagram (also called as ER Diagram, ER Model, ERD) contains entities/attributes and relationships with those entities. ER Model is a methodological approach to create entities in normalized forms to minimise redundancy. It is drawn with the use of Data Modeling Tools and the following steps are done to create the entity relationship diagram. Understanding…

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Data Modeling Topics – Index

Data Modeling Data Modeling Overview Data Modeling Overview Data Modeling Development Cycle Steps to Create a Data Model Data Modeler Role Data Modeling Standards Entity Relationship(ER) Diagram Data Modeling Objects Domains, Defaults & Check Constraints Data Model Repository Data Model Versioning Data Modeling Reports Data Modeling Tools Data Modeling Tools DM Tools: What to Learn?…

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Fact Table

Fact Table | Star Schema: The centralized table in a star schema is called as FACT table. A fact table typically has two types of columns: those that contain facts and those that are foreign keys to dimension tables. The primary key of a fact table is usually a composite key that is made up…

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Designing Snowflake Schema

Snowflake Schema: A snowflake schema is a term that describes a star schema structure normalized through the use of outrigger tables. i.e dimension table hierarchies are broken into simpler tables. In Star Schema example we had 4 dimensions like location, product, time, organization and a fact table (sales). In Snowflake schema, the example diagram shown…

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Designing Star Schema

Star Schema: General Information In general, an organization is started to earn money by selling a product or by providing service to the product. An organization may be at one place or may have several branches. When we consider an example of an organization selling products throughout the world, the main four major dimensions are…

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Time Dimension

In a relational data model, for normalization purposes, year lookup, quarter lookup, month lookup, and week lookups are not merged as a single table.  In a dimensional data modeling (star schema), these tables would be merged as a single table called TIME DIMENSION for performance and slicing data. This dimensions helps to find the sales…

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