What is a database ? Definition of database, Data information, Why do we need a database, Database Management System, Data entry considerations.

What is a database ?

A database is any organized collection of data. Some examples of databases you may encounter in your daily life are:

• A telephone book
• T.V. Guide
• Airline reservation system
• Motor vehicle registration records
• Papers in your filing cabinet
• Files on your computer hard drive.

Definition of database

A database is a collection of information that is organized so that it can easily be accessed, managed, and updated. In one view, databases can be classified according to types of content: bibliographic, full-text, numeric, and images.

In computing, databases are sometimes classified according to their organizational approach. The most prevalent approach is the relational database, a tabular database in which data is defined so that it can be reorganized and accessed in a number of different ways. A distributed database is one that can be dispersed or replicated among different points in a network. An object-oriented programming database is one that is congruent with the data defined in object classes and subclasses.

Computer databases typically contain aggregations of data records or files, such as sales transactions, product catalogs and inventories, and customer profiles. Typically, a database manager provides users the capabilities of controlling read/write access, specifying report generation, and analyzing usage. Databases and database managers are prevalent in large mainframe systems, but are also present in smaller distributed workstation and mid-range systems such as the AS/400 and on personal computers. SQL (Structured Query Language) is a standard language for making interactive queries from and updating a database such as IBM's DB2, Microsoft's SQL Server, and database products from Oracle, Sybase, and Computer Associates.

Quite simply, it’s an organized collection of data. A database management system (DBMS) such as Access, FileMaker, Lotus Notes, Oracle or SQL Server which provides you with the software tools you need to organize that data in a flexible manner. It includes tools to add, modify or delete data from the database, ask questions (or queries) about the data stored in the database and produce reports summarizing selected contents.

Data vs. information : What is the difference?

What is data?
Data can be defined in many ways. Information science defines data as unprocessed information.

What is information?

• Information is data that have been organized and communicated in a coherent and meaningful
• Manner. Data is converted into information, and information is converted into knowledge.
• Knowledge; information evaluated and organized so that it can be used purposefully.

Why do we need a database?

• 1. Keep records of our:
  
  1. Clients
  2. Staff
  3. Volunteers

• To keep a record of activities and interventions;
• Keep sales records;
• Develop reports;
• Perform research
• Longitudinal tracking

Selecting a Database Management System

Database management systems (or DBMSs) can be divided into two categories -- desktop databases and server databases.

· Generally speaking, desktop databases are oriented toward single-user applications and reside on standard personal computers (hence the term desktop).

· Server databases contain mechanisms to ensure the reliability and consistency of data and are geared toward multi-user applications.

Selecting a database system
Need Analysis
The needs analysis process will be specific to your organization but, at a minimum, should answer the following questions:

• How many records we will warehouse and for how long?
• Who will be using the database and what tasks will they perform?
• How often will the data be modified? Who will make these modifications?
• Who will be providing IT support for the database?
• What hardware is available? Is there a budget for purchasing additional hardware?
• Who will be responsible for maintaining the data?
• Will data access be offered over the Internet? If so, what level of access should be supported?

Data entry considerations

· Define “must” enter fields – no record is complete unless: such and such is entered;

Make data entry fool proof. Example: Grade level can be entered as a number (8 or 8^th or eight). By using a pull-down menu with the correct data format these mistakes can be avoided.