Ch5 Flashcards
Database
An organized collection of data that manipulates data and provides an interface
Bit
Bit or binary digit represents a circuit that is eiather on or off. A Byte is made up of 8 bits
Hierarchy of data
Bits, characters, fields, records, files, and databases
Entity
A person, place, or thing for which data is collected , stored, and maintained
Attribute
A characteristic of an entity
Data item
Specific value of an attribute
Primary key
A field or set of fields that uniquely identifies the record
Entity relationships ER diagram
Data models that use basic graphical symbols to show the organization of the relationships between data
Relational model
A simple but highly useful way to organize data into collections of two dimensional tables called relations
SQL
A special purpose programming language for accessing and manipulating data stored in a relational database
Was adopted in 1986 by ANSI as the standard query language for relational databases
Scheme
A description of the entire database
Can be a part of the database or a seperate Schima File
Data dictionary
A detailed description of all the data used in the database
Three characteristics of big data
- volume
- Velocity
- variety
ETL process
Extract
Transform
Load
Data mart
A subset of data warehouse that is used by small and medium sized businesses and departments within large companies to support decision making
Hadoop
An open source software framework that includes several software modules that provide a means for storing and processing extremely large data sets
In memory data base
A database that stores the entire database in random access memory
