April 1, 2025
by Jonathan Frankel
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Don’t forget that Simnet is due Sunday 4/6 11.59PM and LinkedIn (by email) at same time
What is a database?
– Holds data so programs have something to read
– Critical to development of MIS
– Development is by both IT people and “users” (business)
Umass Data Model
Student – Number, Name, Address, Phone, Email,
Class – Letter, Credits, Course, Term, Professor, Classroom?
Professor – Number, Name, Address, Email, Office, Office Hours, Dept, Salary
Usually portrayed with “entity-relationship” diagram
Entity – “person, place or thing” that is critical to business.
– Often called tables, relations or files
Attributes – Details of each entity (or fields)
– Has rules associated with each field (type, length, required)
– This is referred to as Metadata – Data about the data to enforce rules. Ensures no GIGO
Record – One “row” in the database
– Must have a unique identifier called a “primary key”
– In E-R diagram, underline this primary key
– Draw lines with description when there is a relationship
– If one to many, use “crows foot”
– Put “0” where relationship is not required. “cardinality”
– Concept of Referential Integrity
DataBase Management Systems – Enterprise or Individual – Examples: Access, MySQL, Oracle
– Software package that lets computers store data
– SQL – Computer language that lets you create & update tables. Standard across ALL platforms!
– Data Redundancy, Data Inconsistency, Data Security
Other terms – Data Warehouse, Data Mining. Being replaced by Big Data (see trends.google.com)
Fig 6.4 – Accurate, Complete, Consistent, Timely, Unique
DataBase Administrator (DBA) – In change of it all. Especially security and Information Policies.
Slowly, Data Analytics & Data Analysts are figuring out how to use this data, especially visualization.
Compared to Spreadsheets (Easy to use, not a definitive source)
– No relations, no metadata, no primary key, limits on size, no automated collection, single user
Data visualizaion video 200 countries/200 years
Finished up by looking at how companies across many industries are doing data analysis