CHAPTER 12 - DATABASES

DATABASES

1. A database is a system intended to organize, store, and retrieve large amounts of data easily. 
2. It consists of an organized collection of data for one or more uses, typically in digital form.  
3. Digital databases are managed using database management system, which store database contents, allowing data creation and maintenance, and search and other access.  
4. Traditional databases are organized by fields, records, and files. 
5.  A field is a single piece of information; a record is one complete set of fields; and a file is a collection of records.  
6.  Example, a telephone book is analogous to a file, it contains a list of records, each of which consists of three fields: name, address, and telephone number.  
7. An alternative concept in database design is known as hypertext. 
8. In a Hypertext database, any object, whether it be a piece of text, a picture, or a film, can be linked to any other object.  
9. Hypertext databases are particularly useful for organizing large amounts of disparate information, but they are not designed for numerical analysis.        

                     

                             http://www.filebuzz.com/findsoftware/Kernel_Access_Password_Recovery_Serial/1.html  

                                      

                                  http://exonous.typepad.com/mis/2004/03/relational_data.html 

DATABASE MANAGEMENT SYSTEM  (DBMS)

• A collection of programs that enables you to store, modify, and extract information from a database. 
• There are many different types of DBMS, ranging from small systems that run on personal computers to huge systems that run on mainframes. 
• Consists of software that operates databases, providing storage, access, security, backup and other facilities.  
• Database management systems can be categorized according to the database model that they support, such as relational or XML, the type of computer they support. 
• Examples of some commonly used DBMS are MySQL, PostgreSQL, Microsoft Access, SQL Server, FileMaker,Oracle,Sybase, dBASE, Clipper,FoxPro. 
• DBMS may be built around a custom multitasking kernel with built-in networking support, but modern DBMS typically rely on a standard operating system to provide these functions.   
• When a DBMS is used, information systems can be changed more easily as the organization's information requirements change.   

Advantages Database Management System 

• reduced operative expenses 
• quick and accurate decisions based on historical data  
• multi user and change capabilities  
• streamlined and structured workflow capabilities  
• client relationship and business management  
• Facilitated development of new applications program      

Disadvantages Database Management System 

• Database systems are complex, difficult, and time-consuming to design
• Substantial hardware and software start-up costs
• Damage to database affects virtually all applications programs
• Extensive conversion costs in moving form a file-based system to a database system
• Initial training required for all programmers and users   

                                                     http://www.pentasoft.com.my/sw.php?pg=pisf    

       http://www.fig.net/pub/proceedings/korea/full-papers/session24/scheu-rosenbaum.htm     

CITATION :   

• http://en.wikipedia.org/wiki/Database_management_system   
• http://www.webopedia.com/TERM/D/database_management_system_DBMS.html   
• http://en.wikipedia.org/wiki/Database  
• http://www.webopedia.com/TERM/D/database.html  
• http://wiki.answers.com/Q/Benefits_of_database_management_system 
• http://wiki.answers.com/Q/Disadvantages_of_database_management_system  
• http://www.wisegeek.com/what-are-the-advantages-of-dbms.htm