Skip to main content

database


   
 A database is a collection of occurrence of multiple record types containing the relationship between records, data aggregate and data items. A database may be defined as
      A database is a collection of interrelated data store together without harmful and unnecessary redundancy (duplicate data) to serve multiple applications
      The data is stored so that they are independent of programs, which use the data. A common and control approach is used in adding the new data, modifying and retrieving existing data or deletion of data within the database A running database has function in a corporation, factory, government department and other organization. Database is used for searching the data to answer some queries. A database may be design for batch processing, real time processing or on line processing.
DATABASE SYSTEM
      Database System is an integrated collection of related files along with the detail about their definition, interpretation, manipulation and maintenance. It is a system, which satisfied the data need for various applications in an organization without unnecessary redundancy. A database system is based on the data. Also a database system can be run or executed by using software called DBMS (Database Management System). A database system controls the data from unauthorized access.
Foundation Data Concept
A hierarchy of several levels of data has been devised that differentiates between different groupings, or elements, of data. Data are logically organized into:

  • Character


      It is the most basic logical data element. It consists of a single alphabetic, numeric, or other symbol.

  • Field


      It consists of a grouping of characters. A data field represents an attribute (a characteristic or quality) of some entity (object, person, place, or event).

  • Record


      The related fields of data are grouped to form a record. Thus, a record represents a collection of attributes that describe an entity. Fixed-length records contain, a fixed number of fixed-length data fields. Variable-length records contain a variable number of fields and field lengths.

  • File


      A group of related records is known as a data file, or table. Files are frequently classified by the application for which they ar primarily used, such as a payroll file or an inventory file, or the type of data they contain, such as a document file or a graphical image file. Files are also classified by their permanence, for example, a master file versus a transaction file. A transaction file would contain records of
all transactions occurring during a period, whereas a master file contains all the permanent records. A history file is an obsolete transaction or master file retained for backup purposes or for long-term historical storage called archival storage.

  • Database


      It is an integrated collection of logically related records or objects. A database consolidates records previously stored in separate files into a common pool of data records that provides data for many applications. The data stored in a database is independent of the application programs using it and o the ‘type of secondary storage devices on which it is stored.

Comments

Post a Comment

Popular posts from this blog

Pointers in C

Pointers are an extremely powerful programming tool. They can make some things much easier, help improve your program's efficiency, and even allow you to handle unlimited amounts of data. For example, using pointers is one way to have a function modify a variable passed to it. It is also possible to use pointers to dynamically allocate memory, which means that you can write programs that can handle nearly unlimited amounts of data on the fly--you don't need to know, when you write the program, how much memory you need. Wow, that's kind of cool. Actually, it's very cool, as we'll see in some of the next tutorials. For now, let's just get a basic handle on what pointers are and how you use them. What are pointers? Why should you care? Pointers are aptly name: they "point" to locations in memory. Think of a row of safety deposit boxes of various sizes at a local bank. Each safety deposit box will have a number associated with it so that you ca...
30 comments
Read more

Types of Computer Networks(LAN,MAN,WAN)

Types of Computer Networks Computer networks are categorized according to: How they are organized physically. The way they are used. The distance over which they operate. Three main types of computer networks are as follows: LAN   (Local Area Network) WAN (Wide Area Network) MAN ( Metropolitan-Area Network) LAN (Local Area Network) LAN is the most common type of network . LAN stands for Local area Network . It covers a small area. Most LANs are used to connect computers in a single building or group of buildings. Hundreds or thousands of computer maybe connected through LAN. Typical LANs can be found in industrial plants, office buildings, and college or university campuses. LANs are capable of transmitting data at very fast rate. Data transmission speeds of LAN are 1 to 100 megabits per second. It is much faster than data transmission over a telephone line. LAN can transmit data in a limited distance. There is also a limit on the number of...
9 comments
Read more

Ring topologies

Ring topologies are similar to bus topologies, except they transmit in one direction only from station to station. Typically, a ring architecture will use separate physical ports and wires for transmit and receive. Token Ring is one example of a network technology that uses a ring topology.
7 comments
Read more