1. 1 Intro to Info Tech Database Management Systems Copyright 2003 by Janson Industries This presentation can be viewed on line at: http://web.fscj.edu/Janson/cgs1060/wk08.DBMS.ppt

2. Copyright 2012 by Janson Industries 2 Objectives n Explain u Data as a resource u Basic DB concepts F Files, Tables, Records Fields, Keys u Data relationships u Common DBMS functions

3. Copyright 2012 by Janson Industries 3 The Evolving Value of Data n Increase efficiency n Business requirement n Added value

4. Copyright 2012 by Janson Industries 4 Good Information Qualities n Accurate n Timely and accessible n Organized for need

5. Copyright 2012 by Janson Industries 5 Why Databases? n Before DB there were files u Finance created customer file u Marketing, shipping, etc. n Results in u Poor accessibility: files on different computers F Marketing updates don't update finance and shipping data u Duplicate data between files F Extra space F Longer to update F Greater chance of error

6. Copyright 2012 by Janson Industries 6 Database n A structure that organizes data into more efficient groups n DB consists of related groups of data n Ex. create common Customer file and relate Marketing, Finance & Ship files

7. Copyright 2012 by Janson Industries 7 Databases n Different DB types call these groups different things u File RelationTable u Record Tuple Row u Field Attribute Column n DB types u Hierarchical u Relational u Object-oriented n But all duplicate functions of others

8. Copyright 2012 by Janson Industries 8 The Data Hierarchy n Field/Column u Has a unique name, size, and type n Record/Row n File/Table n Database n Keys u Primary – ids each record u Composite u Foreign – relates tables

9. Copyright 2012 by Janson Industries 9 DBMS n Allows users to u Define fields u Group into records u Define keys u Relate tables/files u Insert, change, and delete records of data n Also provides u Data integrity u Security

10. Copyright 2012 by Janson Industries 10 Table Relationships n Defined by the relationship's u Number u Direction of access n The number of the relationship u For a record in one table are there one or many related records in the other table u 1:1, 1:M, M:M n The direction of access u Unidirectional, Bidirectional

11. Copyright 2012 by Janson Industries 11 DBMS n When a record is deleted not really deleted u Marked for deletion – why? n Data integrity: validating u When entered best time F Range – month, day, gpa F Correct type entered – four vs. 4 F Consistent – customer id in DB F Complete – zip code

12. Copyright 2012 by Janson Industries 12 Other DBMS Functions n Query: retrieve and organize data u Language: SQL u GUI: wizards n Reports u Format query results n Forms u Easier to enter data

13. Copyright 2012 by Janson Industries 13 Other DBMS Functions n Backup u Can define a schedule n Recovery u Transaction journaling n Security u Restrict access by DB, individual files, records or fields by user id u Essentially creating alternative views of the data

14. Copyright 2012 by Janson Industries 14 DBMS Software n Lots of vendors u Software companies that create and sell DBMSs n Lots of different DBMS s/w u Even MS has two: Access and SQL Server

15. Copyright 2012 by Janson Industries 15 DB Administration n DB Analyst (DA) designs DB u Interviews users u Defines fields & groups into tables u Defines keys & table relationships n DB Administrator (DBA) implements and maintains DB u Uses DBMS to create DB u Monitors performance u Insures backup and recovery

16. Copyright 2012 by Janson Industries 16 Points to Remember n DB at the heart of all large apps u Grocery checkout, Google, ATMs n DB fails, application fails n Variety of DB types and many DBMS vendors n DBMS provides functions to create, monitor, and protect DB n DBA and DA paid well