2012年8月30日星期四

Your Friendly Neighborhood Database

For the lay person, the term database is just another geek word that is just so prevalent in today’s society. From the office, to the home, and to just about any industry, people refer to their information as being kept in a ‘database’.

So somehow, we all get this idea that the database is some cabinet that holds all the data for a given organization.

But what is a database, anyway?

A database is any collection of data organized for storage in a computer memory and designed for easy access by authorized users. The data may be in the form of text, numbers, dates, or encoded graphics.

Since databases made their debut 1950s, they have become mightily important Night Lights in the everyday operations of every major and even minor industry.

Databases make the output of needed data and Spy Gadgets reports easy, convenient, and almost instantaneous. This is a far cry from the ‘barbaric’ methods once employed Night Lights by every industry.

Those outdated methods included collating data from paper files whenever a report was needed. That process wasted a lot of time and effort. With the help of databases, these manual methods quickly found their demise.

Small databases were first developed or funded by the U.S. government for agency or professional use. But in the 1960s, databases became commercially available to the public.

However, their use was channeled through a few so-called research centers that collected information inquiries and performed them in batches. Online databases—that is, databases available to anyone who could link up to them by computer—first appeared in the 1970’s.

Computer programs that manage and query a database are known as database management systems (DBMS). Database systems are actively studied in information science.

The overriding concept of databases is the idea of a collection of facts, or pieces of information. Databases may be structured in a number of ways, known as database models.

Database Models

Flat Model

The flat (or table) model consists of a single, two-dimensional array of data elements. All members of a given column are assumed to be similar values, and all members of a row are assumed to be related to one another. For instance, columns for name and password might be used as a part of a system security database.

Each row would have the specific password associated with a specific user. Columns of the table often have a type associated with them, defining them as character data, date or time information, integers, or floating point numbers.

This model is the basis spreadsheet systems such as Lotus 123 or Microsoft Excel. However, these applications are not typically thought of as databases per se.

Network Model

The network model allows multiple datasets to be used together through the use of pointers (or references). Some columns contain pointers to different tables instead of data. Many major industries adopted this model in the past few decades.

Relational Model

The relational model is the most popular of the database models today. This model Night Lights is the basis for such database systems as Oracle, mySQL, and even Microsoft Access.

In this model, logically related data is kept in tables not unlike the flat model. However, unlike the network model in which tables are connected via pointers, the relational model is interconnected using keys or values within data rows in tables that point to other tables.

The SQL or Structured Query Language is used to manipulate and derive data from such databases.

James Monahan is Night Lights the owner Gloves for Capacitive Touchscreen and Senior Editor ofTopDatabaseSites.com and writes expert articles about databases.

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