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Data

Raw measurements, anything that can be written down

Information

processed data that has meaning

Database

Tool for data and information storage and management

- shared, integrated computer structure that houses collection of raw data

- contains 2 types of data: End user data & metadata

structural dependence

A database characteristic in which a change in the database syntax affects data access, thus requiring changes in all access programs. (i.e. if a database uses commas to delimit fields, and that changes to dashes it affects a programs ability to access the data)

Data dependence

A data characteristic in which a change in the data format affects data access, thus requiring changes in all access programs. (i.e. if an address field is stored as a string in order of area code, street then city, and if this order is changed to city, street then area code, or if an age field is changed from a int to a double, it affects a programs ability to access the data)

Cons of file system data process

- Long development time

- Requires specialists

- Hard to get quick answers

- needs complex administration

- lack of security

- needs extensive programming

Record

- Instance of a collection of related data

- a row in a data table

- (i.e. an individual student in a student database)

Field

- a single point of data of a record

- (i.e. the age of an individual student)

data independence

The separation of data descriptions from the application programs that use the data. (i.e. Having the ability to change aspects of the data without having to rewrite the application that uses the data)

logical data format

The way a person views data within the context of a problem domain.

physical data format

The way a computer "sees" (stores) data.

data redundancy

occurs when unnecessary duplicate information exists in a database

data anomalies

abnormalities when all changes in redundant data are not made correctly

data anomaly types

Insertion anomalies

Deletion anomalies

Update anomalies

data integrity

When all data in a database is consistent and accurate with reality

DBMS

- database management system

- Collection of programs that stores data structures, relationships between structures and access paths, and controls access to data

DBMS Functions and Properties

- is an intermediary between end use and database, hiding most of internal database complexity. (middleman for logical and physical data formats)

- allows sharing data across multiple apps

- can only access data through it

metadata

data about data (i.e. the time that a photo was taken)