IS 4420 Quiz 1

Data Independence

A condition in which data access is unaffected by changes in the physical data storage characteristics.

Entity Type

A person, place, thing for which data can be stored that is relevant to the organization (nouns)

Entity Instance

A specific occurrence of an entity Often corresponds to a single row in a table If the table is CUSTOMER, an entity instance might be Jacob Case, Kassie, Etc.

Database

An organized collection of logically related data Data and objects that contain the data that are managed by a DBMS

Attribute

Attributes can belong to entities or relationships Entities must have at least 1 attribute, but usually have multiple Relationships may have attributes

Knowledge

Body of information and facts about a specific subject Implies familiarity, awareness, & understanding about the subject EX. "With adequate Knowledge, the best business decisions can be made."

Database Management System (DBMS)

Collection of programs that manages the database structure & controls access to the data stored in the database (software used to manage the database)

Database Careers

DBA, database developer, database architect, BI, ETL

Roles & Advantages of the DBMS

DBMS system presents a single integrated view of the data DBMS software handles the operations required to ensure the data is stored and retrieved correctly & efficiently Security Consistent and improves data integration over the file system approach

Metadata

Data about the user data Describes the data characteristics and the relationships that links the User Data in the database (table & column names, column data types & NULLability, table constraints, primary & foreign key constraints)

Data Dependence

Data access changes when data storage characteristics change

User Data

Data stored by the users of the database to support applications Facts about entities & events of the business Structured data is the atomic data points (numbers, text, dates, etc) Unstructured data is images, videos, documents

Information

Derived from processing data to draw meaningful insights Sorting, aggregations, statistical modeling EX. "By sorting we know which customers were our top 10 most profitable during the year."

Relationship Type

Describe an association between two entities (verbs) Relationships have: cardinality, optionality, degrees, attributes Relationship types: one-to-one, one-to-many, many-to-many

Business Rules

Description of a policy, procedure, principle within an organization Provides standards and constraints Describes how organizations should function, and how the data should be modeled (Declarative, precise, atomic, consistent, expressible, distinct, business-oriented)

Data Model

Graphical representation of a complex real-world data structure (schema) that can be used to implement the database Identifies: entities, cardinality, optionality, degrees, attributes

Database System Environment

Hardware, software (OS, DBMS), people, procedures, data

Data Modeling

Process of creating a specific data model for a specific business process

Data

Raw facts captured & stored in the database Atomic data points such as numbers, dates, strings, etc. EX. "Each data point is a fact, which doesn't have much value beyond what it is describing."

Entity Type

Represents a collection of entity instances Often corresponds to a single table Often named in singular context (EMPLOYEE, CUSTOMER)

Database Server

Server that has DBMS software installed Can host any number of databases

Cardinality

Specifies how my entity instances are allowed on each side of the relationship (1 or many)

Optionality

Specifies if the side of the relationship must have a matching row or not (mandatory, optional)

Relational Model

Tables are related to each other using a shared attribute Relation = table Tuple = row Attribute = column

Data Redundancy

Undesired in relational databases Using file systems instead of databases increases the likelihood of risky data redundancy

Databases Contain 2 Types of Data

User Data & Metadata

System Development Life Cycle

planning, analysis, design, development, testing, implementation, maintenance