Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Entity–attribute–value model wikipedia , lookup
Oracle Database wikipedia , lookup
Microsoft Jet Database Engine wikipedia , lookup
Open Database Connectivity wikipedia , lookup
Functional Database Model wikipedia , lookup
Extensible Storage Engine wikipedia , lookup
Clusterpoint wikipedia , lookup
+ A brief history of data and databases Spanning thousands and thousands of years Unattributed pictures from University of Rochester History Site + Record Keeping – How long? • The earliest “databases” (organized collections of information) may date as early as 3300 BCE (BC) with the beginning of writing (Cuneiform). • Used to keep accounts and other record keeping. • There is evidence that other forms of record keeping (clay tokens, notched bones) were also used prior to this. Source: http://www.ancientscripts.com/cuneiform.html + So what is a database? + Why? We use records to measure “stuff”. And most of these records are not digital. + Today we use search engines, but… • Paper records had to be cataloged in ways that made data update and retrieval possible. • Census worked in precincts, within precinct by address. If you wanted to find one person, you had to know where they lived. When was the first US census? – But of course that was not the intent of the census • Marriage and burial records were in books by year spans. Pages were devoted to last names in ranges. • Paper indexes might be used to cross reference other ways of searching. + Card Catalogs • Interesting way to record the library collection. • Each document (book, journal, artifact, …) was cataloged on a number of dimensions. (subject, author, title, record number (dewey decimal system) • Cards were hand typed and hand filed. • Each catalog provided an index (or a pointer) to where the book was located. • It didn’t indicate whether the book was available, just where it should be found.(example catalog, example cards) + Other storage devices The punched card The first storage device of early computing Roots in textiles in the early 1800’s Jacquard Loom created cards with holes. The hole let a rod through. A set of cards defined the pattern. Binary! Either a rod went through or it didn’t. Loom Basis for the first computing data storage. + Problem As the US Census Bureau approached the 1890 census it had a problem. 1880 census was concluded in 1887 and the population just kept growing. Needed to find a way to increase the efficiency of the census processing. Enter Herman Hollerith. + Hollerith’s device pantograph Hollerith card Integrating machine + First computers The program, the data, the JCL – all done with punchcards + Electronic files • Originally, files were associated with particular applications on particular computers. • Different kinds of data were in these different files. • Integration of data was very difficult. • Different uses of the data required program change. • File storage was expensive and limited. • File storage was primarily sequential (slow access) + Enter the database • Objects in a database can be related to one another. • Hierarchical – One record leads the the related record. (Like a tree) • Network – Allowed for multiple relationships (like a network) • The databases used pointers to relate one record to another. • 1960’s through today + 1970, Edgar Codd Relational DBMS • Mathematician at IBM • Based on Relational Calculus U of M • MicroDBMS IBM • System R • First implementation of SQL Led to • Oracle • IBM DB2 •Informix • Sybase • MS SQL Server (based on Sybase) + Relational Ideas See prior day’s lecture + The Future? • Object Oriented Databases – – – – – • Combine data and operations on those data Allows for inheritance Cache’ (Intersystems Corp) Oracle (Object-Relational Database) Postgre(open source) XML and XML DBMS – – XML designed to transport and store data (w3schools.com) Database manages that data