Computer Fundamentals & Programming. (Course No: cse 311) Contents



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GROUP WORK CAPBILITIES:-

To work in a group using computer terminals sharing files, software tools and facilities of the common file server are called group-ware and work flow automation. In another word groupware is an umbrella term describing the electronic technologies that support person-to-person collaboration. Groupware includes E-mail, Electronic Meeting System (EMS), Desktop Video Conferencing (DVC) as well as systems for work flow and Business Process Reengineering (BPR).

To-day software vendors are integrating collaboration technologies into their products. Groupware maximizes human interaction while minimizing technologies interference. The term 'Groupware' and ‘Collaborative Computing' are often used interchangeably when in fact they are different. Groupware is basically a subset of collaborative computing. Collaborative computing refers to the technology that is hardware, software and structures that support group working.




  1. MAIL ENABLING:-

As you know windows program has a "Send" command and windows 2000 has a "Send to" command in its "File Menu". If you choose and click on "Send to" command of File Menu you will find mail recipient menu, Fax recipient, etc. When you click on mail recipient, then the document will be sent as an attachment using your default e-mail client to the address you specify. This is the new facilities added to the application software. This is an example of the advanced and more sophisticated mail enabled applications software. Mail enabled applications are designed to capitalize on e-mail.


  1. WEB ENABLING:-

As you know to-day most of the information are available in the internet. Therefore software vendors are adding the facilities into their product to link the internet and down load the required information. Most software applications are now web-enabled. During installation, most of the applications will automatically connect to the internet and to the vender's web site and will register their products.

For example, Word 2000 can now connect to the Microsoft's website and get clipart new images if the user wants to put in his computer, thus the options available to the user are more now. In the future also they will have more and more web enabling facilities in the new software.



11. DATA PROCESSING:-

Data processing is defined as the processing of data to make it more usable and meaningful information. Data means raw facts or observations in terms of any numerical numbers. It can be any words, numerical numbers, any codes or any mixture of numerical numbers and alphabets, similarly data could be voice, text, images or any numeric data too. Data means a file of records. A record means a set of fields. Data processing means to collect, manipulate and organize the data in a logical order. Then its content is analyzed, evaluated and placed it in a proper order for the end user. Thus the raw data is manipulated by calculating, sorting, comparing, classifying and summarizing to convert into the required information. The quality of the any data stored in an information system must also be maintained by editing and update time to time.




    1. TYPES OF DATA PROCESSING:-

There are two types of data processing as given below:

  1. File processing

  2. Database processing




  1. FILE PROCESSING:- After collection data, it is processed in separate files. This process is called file processing. Again file processing can be divided into two categories like sequential and direct access.




  1. SEQUENTIAL FILE PROCESSING:- Data stored in a tape is in a sequence order. If such data is processed that is called sequential data processing or sequential file processing.

Some time there will be group wise data collection (batch wise e.g. district wise or date wise or others) in the different files. Those data files will be merged in a file. Then the master file will be sorted in some sequence and lastly processed it. This type of processing is called sequential file processing.


  1. DIRECT- ACCESS FILE PROCESSING:- Nobody can have direct access in a data file stored in a tape. But except tape, anybody can have direct access into the data stored floppy disk, hard disk or compact disk (CD).

For the direct access file processing, the data file must be organized for the direct access that means the data file must be created in the floppy or hard disk or CD with some unique codes or index numbers.


  1. DATABASE PROCESSING:- A database means a self describing collection of integrated records. Most of the databases contain a directory of its contents. It can contain multiple related files. A file means a collection of records. A record consists of different fields. User define data fields and make entry of fields into records. Then they combine records to a file. Now users can manipulate and retrieve stored data in database in various ways to prepare reports and collect certain desired information arranged in some order.

In a relational database a file arranged in a tabular form. The table contains rows and column. Each column of a table represents fields and each row represents a record. The relational database management package has ability to manage data in more than one file. The data of one file is related to the data of another file through the use of common field. The database management packages have also data manipulating and data analyzing capability. It can also produce graphs from data in the database. All these activities are called database processing.


A number of database management packages are available such as dBASE, ORACLE, UNIFY, FOXBASE, SAYBASE and INFORMIX, etc. In database processing the database management system (DBMS) acts as an intermediary between user and the database.
12. INTRODUCTION TO DATABASE MANAGEMENT SYSTEMS:-

Information is the most important resource of the organization or knowledge. It helps managers to make right decision for the future planning of the organization. Data, images, texts, documents and voice can be an input data to convert into information. The user receives the information and then makes a decision and takes an action. Information is power.


12.1 QUALITY OF INFORMATION:

By any means the quality of information must be maintained. That means, the information must be accurate, timely and relevant.


(a) ACCURACY

Accuracy of information means error free information.


(b) TIME LINES

Timelines means that the user can get the information when they need it. In fact it is prompt.


(C) RELEVANCY:

Relevancy means the use of a piece of information for a particular person. It is very subjective and personal matter. Information relevant for a one person may not be relevant or useful for another.


12.2 WHAT IS DATABASE?

A collection of data designed to be used by different user is called database. In other word a database is an organized collection of related information about particular subject or purpose. For example, the information regarding the price of a book or profile of an individual in any organization.


Another example, create a database of a library. The database is designed in such a fashion that the user can find out the price wise, edition wise, author wise or publication wise etc. at any time.
In computer a database is also like a box containing index cards. The only difference is that instead of index cards, a computer database is filled with records. While each index cards in a box contains information’s written in many lines, a record in a database contains all the information related to an item in just one line. Information in a database is stored in rows (records) and columns (fields) in a sequence of unique number.

12.3 WHY DATABASE?

As you know, database is an organized collection of related data. It is an integrated collection of records which contains different fields like name, address and telephone number. The telephone directory could be a simple example to answer this question. The user Mr. A can use this database for finding telephone number of a particular person or Mr. B can use it for finding a person’s name of a particular telephone number and third user Mr. C can use the same diary to find a list of similar names and their telephone numbers within the same city code. Thus a telephone diary (a database) could be used in three ways or more. Therefore the database is created to fulfill user’s need for different purpose.


Similarly from a database of a library file, the user can find the list of books like edition wise, publisher wise, subject wise, or writer wise etc. But to find these four lists, the user must needs to process the database four times. Therefore, to run a database there must be software and a system to arrange the records within the database. Such system software is called database management system (DBMS). Without this software, if somebody creates the database, there will be many problems during the database preparation. The problems may be as follows until a final database is prepared.
Types of problems in creating a database:

(i) Data repetition

(ii) Data inconsistency

(iii) Data security to maintain

(iv) Wrong coding within the range

(v) Wrongly entered data

(vi) Data sharing may not be possible

(vi) Data lost etc.


At last, the user prepares a final error free and clean database after facing all the above said problems. Then the characters of the data in a database should be as follows.

(i) SHARED - Among different users, the data in a database are shared.

(ii) SECURITY - The data of the database is totally secured from the un authorized persons.

(iii) CONSISTENCY - The data of the database is maintend the consistency.

(iv) VALIDITY/CORRECTNESS - The data of the database is error free. Using all the methods all the errors is already deleted.
12.4 WHAT IS A DATABASE MANAGEMENT SYSTEM?

A database management system (DBMS) is a set of programs or a software which provides services for accessing a database, while maintaining all the required features of the data. Some of the major services of a DBMS are as given below.

(i) Transaction Management

(ii) Security Management

(iii) Recovery Management

(iv) Programming Interface

(v) Concurrency Control

(vi) Storage Manager

(vii) Application
Hence DBMS is a software that creates, manages, protects, and provides access to a database.
(i) TRANSACTION PROCESSING:

A transaction of data means creating, updating, deleting one record or modifying a set of records in sequence. Similarly transaction processing means daily processing of records in sequence. For example any accountant officer users computer for entering new records steps by steps and processor it accordingly.


(ii) CONCURRENCY MANAGEMENT:

Concurrency management means co-ordinating the actions of database manipulations concurrently in the shared data during data processing. For example if one user manipulates a record, the effect is distributed in the other shared records too.



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Services provided by a DBMS
(iii) RECOVERY MANAGEMENT:

Recovery management is a facility used in the DBMS. Recovery mechanisms in a DBMS make sure that the database is returned to a consistent state after a transaction fails or aborts. For example a DBMS, if a record is incomplete or damaged the program skips it and does process again during processing time.



(iv) SECURITY MANAGEMENT:

DBMS can make sure that only authorized users are given access to the data in the database. This is called the security management or a protection of a database from the unauthorized persons.


(v) LANGUAGE INTERFACE MANAGEMENT

The DBMS provides support programming languages used for the definition and manipulation of the data in the database. The data structures are created using the data definition language commands. The data manipulation is done using the data manipulation command. This is the example of language interface management of the DBMS.


(vi) DATA CATALOG (Data Dictionaries)

In any type of DBMS there is a data catalog system. Data catalog or Data Dictionary is a system database that contains the descriptions of data in the database. It contains information about data, relationship, constrains and the entire schema that organize these features into a unified database.


(vii) STOREAGE MANAGEMENT

The DBMS provides a facility of permanently storing of the data. The storage manager interfaces with the operating system to access the physical storage. The internal schema defines how the data should be stored by the storage management mechanism.


12.5. WHY DBMS?

A DBMS provides a secure and survivable medium for the permanent storage and retrieval of data. It can provide many facilities like transaction processing, programming interface, security management, recovery management, concurrency management and storage management, etc. DBMS is very easy to use, access and manipulate the data in the database.


12.6 TYPE OF DATABASE MANAGEMENT SYSTEM:-

There are five types of the database management system like (i) Hierarchical (ii) Network (iii) Relational (iv) Object oriented and (v) Deductive. These are the five DBMS models, which are running in the world markets at present.


(i) HIERARCHICAL

Hierarchical Model is running since 1950 AD. It is an oldest DBMS Model. It assumes that a tree structure is the most frequently occurring relationship. This assumption is recognized today a misleading.

For example, hierarchical model is similar to company’s organizational structure. At the top we have GM. Under him there are 2, 3 deputi general managers (DGM). Just below DGM there are 6,7 department heads and so-on. Here the row position implies the relationship to each other from top to bottom. It looks like a tree structure.
(ii) NETWORK

To-day, the hierarchical model is replaced by Network model. The Network model can be used in a book distributor as an example. A book can have many attributes like. Title, Author, Publisher, Year of publication, distributor, cost etc. Similarly on the other hand, a distributor can have attributes like Name, Contact address, Discount and others. We can use these both examples in the network model.


(iii) RELATIONAL MODEL

A relational database organizes data in a table format consisting or related rows and columns. Each location in a table contains a single piece of data, known as data item. Each column of a table represents a field, which consists of data items. A full set of data in any given row is called a record. The whole related records makeup a file. In a relational database a file is also called a relation. The relational model uses the rows and columns of tables to organize the data elements. The relational model is currently the most popular database mode.

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