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Welcome. Management Information Systems Session 2 Data Bases. Who uses them??. Banks Airlines Business Libraries Governments, FBI, CIA, Interpol Artisists, film makers Scientists, DNA sequences… Astronomers…Chemeists…. Who does not?. ????? 8-12 billion USD annual
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Welcome Management Information Systems Session 2 Data Bases
Who uses them?? • Banks • Airlines • Business • Libraries • Governments, FBI, CIA, Interpol • Artisists, film makers • Scientists, DNA sequences… Astronomers…Chemeists…
Who does not? • ????? • 8-12 billion USD annual • IBM, Oracle, Informix, Sybase, NCR, Microsoft, MySQL,…
History • 1890 US Census asked Herman Hollerith to develop punch card machine. • Hollerith founded company, merged with another firm which became IBM. • Computer development fuelled by military in WW1, to track logistics and production of weapons. WWII, advanced optimization and cryptography • 1960 US DOD commissions COBOL (Common business oriented language) • Codasyl (US Gov) and IMS (IBM and NASA)
History • "A Relational Model of Data for Large Shared Data Banks," Edgar F. (Ted) Codd Communications of the ACM 1970. • Data independence from hardware • High level procedural language to manipulate data • IBM had IMS • System R (SQL) • Ingres (US Military, UC Berkeley)
History • Ingres & System R employees circulate through Silicon valley circles • 1980 IBM SQL/DS hits market • Codd awarded ACM Turing Award • 1980s - Oracle marketing demonstrates superiority of relational model
Terminology • Data sources • Database: persistent collection of data • Database Management System (DBMS): software that controls access to the database • Database Administrator (DBA): person who controls database • Data Model: general structure of the data in the database • Data Language: commands used to define the data model and give users access to the database; SQL(Structured Query Language)
Normal Forms • Non-normalized data • 1NF • no repeating fields or groups of fields • all values in field are “atomic” • 2NF • Already in 1NF • Each non-key field is FD on entire primary key • 3NF • Already in 2NF • no non-key element is FD on any non-key element
Normal forms inclusive ONF2 1NF 2NF 3NF BCNF 4NF 5NF Up 270+ Normal forms in Lit – Academic abstractions
To 1NF What if some companies have 3 URLS? 4, 5, …N?
1st Normal Form We have solved the URL problem, But created another…. Eliminate horizontal redundancies
2nd Normal Form Primary Key Foreign Key Eliminate vertical redundancies
3rd Normal Form All columns must relate directly to the primary key
Open Source… • www.opensource.org • Linux (OS) • Apache (Web Server) • MySQL (DB) • PhP (Scripting) • JBoss (Web Server) • Samba (file & content) • OpenOffice (Office Apps.) • Many more…
Open Source Pros.. • Cost.As far as software acquisition costs go, open source products are free. • Flexibility.Just like Linux, open source software frees companies from vendor lock-in. • Close to the code.With open source, enterprise users can pinpoint problems in specific code and suggest patches to solve problems. • Growing support.Vendors such as HP, Red Hat and Novell are enhancing support for open source products beyond Linux.
Open Source Cons.. • Cost. While acquisition costs are free, corporate users must pay for support and services, and there are often costs associated with training IT staff. • Integration. Today, users are on their own when it comes to integrating open source products into legacy infrastructure, although this is starting to change with companies as varied as Gluecode and HP rolling out support for open source stacks. • Capabilities. Today’s open source databases and application servers are technically very good, but still not up to par with heavy-duty commercial offerings such as DB2 or WebLogic. • Intellectual property. The SCO Group’s legal assault against Linux should serve as a warning shot for any company considering open source. Understand the open source license governing the product and what your rights and responsibilities are.