The main advantages of using database is fast and efficient data retrieval. Database enable user to break data into specific parts to helps you rapidly query the data in the way you requested. We take the hypermarket sales as example, the marketing manager can store the sales details of every product in related databases, in such way, the question "What is the sales of product X for the last 3 months?" can be very easy and accurate to be answered. If all the information of the thousands of product available in the supermarket recorded into a large text file, its impossible to find out the data of specific product item.
Database also allows you to set up rules to ensure the data remains consistent and up-to-date when you modified it. You can set a unique ID for each of every product (unique identifier) so that all the product won't get mixed up, or else, telling the sales data of a product becomes impossible. A properly set-up database makes work efficiency and minimizes data redundancy.
Modified from : http://e-articles.info/e/a/title/Why-and-When-to-Use-a-Database/
Sunday, March 20, 2011
Physical & Logical Views of Data
A database management system provides the ability for many different users to share data and process resources. But as there can be many different users, there are many different database needs. The question now is: How can a single, unified database meet the differing requirement of so many users?
A DBMS minimizes these problems by providing two views of the database data: a logical (external) view and physical (internal) view. The logical view/user's view, of a database program represents data in a format that is meaningful to a user and to the software programs that process those data. That is, the logical view tells the user, in user terms, what is in the database. The physical view deals with the actual, physical arrangement and location of data in the direct access storage devices(DASDs). Database specialists use the physical view to make efficient use of storage and processing resources. With the logical view users can see data differently from how they are stored, and they do not want to know all the technical details of physical storage. After all, a business user is primarily interested in using the information, not in how it is stored.
One strength of a DBMS is that while there is only one physical view of the data, there can be an endless number of different logical views. This feature allows users to seedatabase information in a more business-related way rather than from a technical, processing viewpoint. Thus the logical view refers to the way user views data, and the physical view to the way the data are physically stored.
http://astahost.com/info.php/logical-physical-view_t20654.html
A DBMS minimizes these problems by providing two views of the database data: a logical (external) view and physical (internal) view. The logical view/user's view, of a database program represents data in a format that is meaningful to a user and to the software programs that process those data. That is, the logical view tells the user, in user terms, what is in the database. The physical view deals with the actual, physical arrangement and location of data in the direct access storage devices(DASDs). Database specialists use the physical view to make efficient use of storage and processing resources. With the logical view users can see data differently from how they are stored, and they do not want to know all the technical details of physical storage. After all, a business user is primarily interested in using the information, not in how it is stored.
One strength of a DBMS is that while there is only one physical view of the data, there can be an endless number of different logical views. This feature allows users to seedatabase information in a more business-related way rather than from a technical, processing viewpoint. Thus the logical view refers to the way user views data, and the physical view to the way the data are physically stored.
http://astahost.com/info.php/logical-physical-view_t20654.html
What is Data???
In computing, data is information that has been translated into a form that is more convenient to move or process. Relative to today's computers and transmission media, data is information converted into binary digital form.
In computer
component interconnection and network communication, data is often distinguished from "control information," "control bits," and similar terms to identify the main content of a transmission unit.
In telecommunications, data sometimes means digital-encoded information to distinguish it from analog-encoded information such as conventional telephone voice calls. In general, "analog" or voice transmission requires a dedicated continual connection for the duration of a related series of transmissions. Data transmission can often be sent with intermittent connections in packets that arrive in piecemeal fashion.
Generally and in science, data is a gathered body of facts.
Some authorities and publishers, cognizant of the word's Latin origin and as the plural form of "datum," use plural verb forms with "data". Others take the view that since "datum" is rarely used, it is more natural to treat "data" as a singular form.
In computer
component interconnection and network communication, data is often distinguished from "control information," "control bits," and similar terms to identify the main content of a transmission unit.
In telecommunications, data sometimes means digital-encoded information to distinguish it from analog-encoded information such as conventional telephone voice calls. In general, "analog" or voice transmission requires a dedicated continual connection for the duration of a related series of transmissions. Data transmission can often be sent with intermittent connections in packets that arrive in piecemeal fashion.
Generally and in science, data is a gathered body of facts.
Some authorities and publishers, cognizant of the word's Latin origin and as the plural form of "datum," use plural verb forms with "data". Others take the view that since "datum" is rarely used, it is more natural to treat "data" as a singular form.
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