Database+Basics

media type="custom" key="4399621"​ **What is a database and how does it organize information?** A [|database] is a computerized systems for storing information in an organized manner so that it can be searched for and retrieved when needed. Information is stored in the form of **fields, records,** and **files.** Businesses, government groups, private organizations, and academic institutions all use databases, and they represent the dominant use of computing power in the business world today. Schools use databases to store and handle grades, class schedules, tuition payments, library fines and other records relevant to education. Executives consult company databases to aid in their decision making. If a company is considering opening a new branch office, managers and other strategic planners can carefully examine databases describing the purchasing habits of local consumers in order to choose the best location. The ability to associate or organize stored data in a variety of meaningful ways represents the power of database software ** Levels of Data within a Database -** The ability to organize and reorganize data for different purposes is due to two database characteristics: their vast storage potential and the way the organize data. Traditional database organizes data in a hierarchical fashion, containing information about entities in the form of fields, records, and files. [|Entities] - An //entity// is a person, place, thing, or event //(sales transactions, student grades, traffic violations, and telephone records).// [|Fields] - The smallest element of data in a database is a //field//. A field generally has three attributes: [|Records] - A collection of related fields describing an event or situation is called a record. Mailing information would likely include fields for name, address, city, state, and postal code.
 * Data vs Information ** - The terms [|data] and //information// are key concepts in understanding the importance of computerized databases. Data is a collection of raw, unorganized content in the form of words, numbers, sounds, or images. Data associated with other useful data on the same topic becomes information.
 * Historical Database Form -** Databases as storage systems existed long before computers came into being. These documents were ususally collected and organized in filing cabinets. Locating information and structiong it for various purposes was possible, but it involved sifting through stacks of pater, identifying the desired data, and then writing or typing selected items on more paper so that people could analyze the information. Today the same task could be executed in minutes using a computerized database. Other than independent medical offices and some small retail shops, paper-based storage systems are rarely encountered.
 * The Importance of Accurate Data** - Databases are records of events or situations, so they must be continually updated to ensure that the data they contain is accurate. Any inaccuracy will creat an avalache of problems throughout the different company departments and will reduce the quality of the data in the database. Data quality is particularly important when considering that summarized information is often used for decision making.
 * **data type:** usually numeric data //(consists of numbers only)// or alphanumeric data //(consists of numbers, text, and special characters)//
 * **name:** assigned by person developing the database
 * **size:** number of characters that can be entered
 * Files** - A //database file// is a collection of records of the same type. The three key decisions in making a database are: What records will be used, which fields will be in those records, and which data type and size each field will have. The record layout is used as the basis for each record in the table.