COSC 301

Database system properties

-*Efficient* : handles large data -*Convenient*: Easy to write queries to retrieve data -*Safe* : protects data from system failures and hackers - *Massive*: database sizes in gigabytes, terabytes, petabytes -*Persistent* : even in power failure -*Multi-user*

Measure Data

-Kilobyte (KB) -Megabyte(MG) -Gigabyte(GB) -Terabyte(TB) -Petabyte(PB) -Exabyte(EB) -Zettabyte(ZB)

Database

A collection of logically related data for a particular domain -Data stored

Computer

A device that can be programmed to solve problems

Database management system (DMS)

A software designed for the creation and management of databases

Pivot tables

Allow for easily aggregating and exploring large data sets

Relational database

Allow for the storage and analysis of large amounts of data

Aggregate function

Computes a summary function over a range of cells. The values can either be data values or cell locations -MIN() -MAX() -SUM() -AVERAGE() -COUNT() -MEDIAN()

Pivot chart

Is a chart attached to a pivot table

Memory

Is a device which allow the computer to store data either temporarily or permanently (data is preserved when no power)

Measure size

Is a measure of memory storage capacity in bytes

Attribute

Is a named column of a relation

Data analyst

Is a person who uses tools and applications to transform raw data into a form that will be useful

Tuple

Is a row of a relation

Domain

Is a set of allowable values for one or more attributes

Relation

Is a table with columns and rows

Metadata

Is data that describes other data -Names of files -Column name in a spreadsheet -Table and column names and types in a data base

Data

Is information before it has been given any context, structure, and meaning

Software

Is programs the computer follows to perform functions

Data analysis

Is the processing of data to yield useful insights or knowledge

Degree

Of a relation is the number of attributes it contains

Relational Model

Organizes data into tables called relations

Analog

Real world where the information is encoded on a continuous signal (spectrum of values) (i.e. liquid level expansion over a range in the thermometer)

Digitally

Represent data in discrete bits (i.e. the units on a thermometer)

Absolute address

The dollar sign $ is a symbol that indicates an absolute address

Cardinality

The number of tuples it contains