Chapter 3 Flashcards
Database
o Collection of related data that is stored in a central location or in multiple location, Similar to filing cabinet
Components of a database
Data File
oGroup of related records
Record =row
oGroup of related fields
Field
o = a column
Physical view
is how data is stored (ex: disks) and only one of these on database
Logical view
ois how data is organized, retrieved and presented to users can be more than one
Hierarchical Database Models
o Has a tree like structure where records are called nodes, node at top is root, relationships among are called branches
Network Database Models
o Each record has multiple parents and child records
2 Relational Models (Primary & Foreign Key)
Primary key: Unique identifier for each record.
o Foreign key: A foreign key shows up when a primary key from another table appears in another.
o Primary and foreign keys are extremely important as they link different tables together.
- DBMS
o Software for creating, storing, maintaining, and accessing database files
Software of DBMS
Database Engine
•Heart of DBMS responsible for storage, manipulation, and retrieval
Data definition
• Create and maintain data dictionary
Data manipulation
• Add, delete, retrieve, and modify what happens
Application generation
• Used to design elements of an application using database
Data administration
• Used by IT pros or data admin (backup, security)
accessing database files
Distributed Data
ads and dis
o Data stored on multiple servers
o Is faster and minimizes the cost of failures
o Not as secure
Centralized data
o Data stored in one location
o Secure
o Is slower and failures are more expensive
Data Warehouse
collection of data from variety of sources used to support decision making
Data Mart
ad and dis
Smaller version of data warehouse used by a single dept
o Advantages
• Normally faster
• Easier to crate as less complex
• Less costly
• Users are targeted better as data mart it focused on specific dept
Raw Data:
This data is a bunch of numbers with no organization
Summary Data
: Data has been organized to be efficient data
Meta Data:
This data tells us about data
Five V’s of Big Data
Volume
o Quantity of transactions
Variety
o Structured, unstructured
Velocity
o Speed data is being collected
Veracity
o Accuracy of data
Value
