Lecture 1 Flashcards
the foundation of technological
activity
Data
a highly organized collection
of assembled data
Database
sophisticated software that controls the database and the database environment
Database Management System
tokens or “counters” that were used for record keep dates back to what year
8500 B.C
the recording of data to keep track of how much a person has produced and what it can be bartered or sold for.
Record-keeping
originated in the trading
centers of fourteenth century Italy.
Double-entry bookkeeping
The earliest known example of double entry bookkeeping is from a merchant in Genoa and dates to the year
1340
he produced an adding machine that was an early version of today’s mechanical automobile odometers
Blaise Pascal
Invented in 1805 by Joseph Marie
Jacquard of France.
Punched Cards
method of storing fabric patterns, a form of graphic data, as holes in punched cards was a very clever means of data storage
Punched Cards
punched cards were invented by
Jacquard of France 1805
he arranged to have the census data stored in punched cards and invented machinery to tabulate them.
Herman Hollerith
In 1896 Hollerith formed the Tabulating Machine Company to produce and commercially market his devices – this later became
IBM
he developed devices to automatically feed cards into the equipment and to automatically print results
James Powers
In 1911 he established the Powers Tabulating Machine Company – this later became Unisys Corporation
James Powers
Time Periods:
The introduction of electronic computers.
Witnessed a boom in economic development.
From this point onward, it would be virtually impossible to tie advances in computing devices to specific, landmark data storage and retrieval needs
Mid - 1950s
The earliest form of modern data storage, introduced in the 1870s and 1880
Punched paper tape
these were the only data storage medium used in the increasingly sophisticated electromechanical accounting machines of the 1920s, 1930s, and 1940s.
Punched cards
Time Periods:
Era of erasable magnetic storage begins.
Early development of magnetic tape for data recording.
Magnetic tape concept developed for commercial use by multiple companies.
1930s,1940s, 1950
commercially available units in
1952.
Magnetic Tape
began to be
developed at MIT in the late 1930s and early 1940s
Direct Access Magnetic Devices
early 1950s; forerunners of
magnetic disk technology
Magnetic Drum
commercially available in mid
1950s
Magnetic Disk
introduced as a data storage
medium in 1985
Compact Disk (CD)
Flash drives
Solid-state technology
Involves a company protecting its data from theft,
malicious destruction, deliberate attempts at making phony changes to the data.
Data Security
Ensuring that even employees who normally have access to the company’s data are given access only to the specific data that they need in their work
Data Privacy
The ability to reconstruct data if it is lost or corrupted.
Backup and Recovery
Data is often stored multiple times within a company’s system. New applications create additional data files. Duplication occurs within single files and across multiple files.
Data Accuracy
A collection of related data
Database
Known facts that can be recorded and have an implicit meaning.
Data
Some part of the real world about which data is stored in a
database. For example, student grades and transcripts at a
university.
Mini-world
A software package/ system to facilitate the creation and maintenance of a computerized database.
Database Management System (DBMS)
The DBMS software together with the data itself. Sometimes, the applications are also included.
Database System
Defines database structure, data types, and constraints.
Loads initial database contents onto secondary storage.
Manipulates data: Retrieval (querying, reports), Modification (insertions, deletions, updates).
Access via web applications.
Supports concurrent user and application access while maintaining data validity and consistency.
Typical DBMS Functionality
is used to hide storage details and present the users with a conceptual view of the database.
Data Abstraction
is a major part of database applications. This allows hundreds of concurrent transactions to execute per second.
OLTP (Online Transaction Processing)
guarantees that each transaction is correctly executed or aborted
Concurrency control
ensures each completed transaction has its effect permanently recorded in the database
Recovery subsystem
Users are categorized into
“Actors on the Scene”
“Workers Behind the Scene”
Actors on the scene:
Responsible for authorizing access to the database, for coordinating and monitoring its use, acquiring software and hardware resources, controlling its use and monitoring efficiency of operations.
Database administrators:
Actors on the scene:
Responsible to define the content, the structure, the constraints, and functions or transactions against the database. They must communicate with the end-users and understand their needs
Database Designers
Actors on the scene:
They use the data for queries, reports and some of them update the database content.
End-users
Actors on the scene:
End-users can be categorized into
Casual: access database occasionally when needed
Naïve or Parametric: they make up a large section of the end-user population.
Database End Users:
These include business analysts, scientists, engineers, others
thoroughly familiar with the system capabilities.
Many use tools in the form of software packages that work
closely with the stored database
Sophisticated
Database End Users:
Maintain personal databases with packaged applications.
Example: Tax program users with internal databases.
Example: Individuals managing personal photo and video databases.
Stand-alone
Actors on the Scene:
This category currently accounts for a very large proportion of the IT work force
System Analysts and Application Developers
Actors on the Scene:
They understand the user requirements of naïve and sophisticated users and design applications including canned transactions to meet those requirements.
System Analysts
Actors on the Scene:
Implement the specifications developed by analysts and test and debug them before deployment
Application Programmers
Actors on the Scene:
There is an increasing need for such people who can analyze vast amounts of business data and real-time data (“Big Data”) for better decision making related to planning, advertising, marketing etc.
Business Analysts
Actors behind the Scene:
Create and test DBMS modules, interfaces, and ensure compatibility with other system components
System Designers and Implementors
Actors Behind the Scene:
Design software tools for database modeling, performance monitoring, prototyping, etc., aiding application development and database usage
Tool Developers
Actors Behind the Scene:
Manage hardware and software maintenance and operation of the database system.
Operators and Maintenance Personnel
Historical Development of Database Technology:
these were introduced in mid 1960s and dominated during the seventies
The Hierarchical and Network Models
Historical Development of Database Technology:
was originally introduced in 1970, was heavily researched and experimented within IBM Research and several universities
Products emerged in the early 1980s
Relational model
Historical Development of Database Technology:
were introduced in late 1980s and early 1990s to cater to the need of complex data processing in CAD and other applications
Object-Oriented Database Management Systems
(OODBMSs)
Category of Users:
Utilize and manage database content, design, develop, and maintain database applications.
“Actors on the Scene”
Category of Users:
Design, develop DBMS software, related tools, and manage computer systems operations
“Actors Behind the Scene”
