Explain what is Database ? (Or) Disucss the architecture of Database?

A database is a collection of organized information.  The information is stored in a database, is in the form of a table., arranged in a file in the form of columns and rows. The data can be anything such as facts and figures, which is useful and important. For example, it can be a name of a person, name of city, or a telephone number.

When the data is useful to the user, after processing, then it is called Information. Thus, the data should be clear, meaningful and unambiguous. The data thus stored in the database is used to maintain the database for any organization.

The English dictionary is one of the good example of a database, where data is arranged in an alphabetical order. Another example of database is a telephone directory, in which the subscribes list is arranged in an order. The information in a database can be used to store the data, process the data, and also can retrieve (get back) the data at any point of time.

When you want to have a database, first you need to plan and design the structure of the database. The structure of the database contains field names, field types (data type), width and decimals, if any.  The fields are identified by the field name and they are the individual items having its datatype and integrity constraints.

Each column is known as a field and collection of fields is called a record or row. The collection of all records is known as a database.

Once the database is designed, it requires to perform certain operations in it, such as

·         Inserting new data into the database

·         Process the data stored in the database

·         Modifications / updating for the data

·         Deletion of unnecessary records

·         Re-organizing the database either in Ascending or Descending order

·         Generating the reports from the database etc.

When such a database requires to perform the above operations frequently is called a Database Management System (DBMS). For example, the following is a student information database, with the following structure

Field Name	Field Type	Width	Decimal
STUCODE	N	4	-
FNAME	C	20
ADDRESS	C	30
CITY	C	15
TELNO	N	10	-

  The table, after insertion of the data looks as follows.

STUCODE	SNAME	FNAME	ADDRESS	CITY	TELNO
9543	Srinivas	Mohanrao	12-1-2/A	Hyderabad	684436343
9061	Vijay Mathur	Gopalaraju	Ambika Nagar	Vijayawada	865464546
9111	Anirudh	Anand	12-1/G7 Near Society	Kakinada	935565350
…..	…	…	…	…	…
…..	…	…	…	…	…
….	…	…	…	…	…

STUDENT INFORMATION DATABASE

Therefore, a DBMS is a collection of inter-related data stored in a database and the collection of programs written by the Programmers, used to access the data stored in the database. The primary goal of the database is, to provide an easy environment to store the data, retrieve the data, update the data, process the data and query the data at any time. The database is used for bulk storage of information and an easy mechanism that should provide security and integrity constraints. 

DBMS is mainly consists of 4 components, as

      1.      Data                      2.  Hardware               3. Software                  4. Users

DATA:  The data should be clear, meaningful and unambiguous since it is shared by different users and the system may be used by multiple users for different tasks.

Hardware: The hardware should have the required capacity to store software, large volume of the data in its Hardware components such as magnetic disks, tapes.

Software: The software is a collection of set of programs and physical database that share the database, upon the software selection.

Users:  The users are classified into 3 types, such as

      a)       Application programmers

      b)       End Users

      c)      Database Administrators

Application Programmers:  The Programmer’s are used to develop the application programs for the database.

The End users are the actual people who use the software and application programs developed by the Programmers.

The Database Administrator (DBA) will take care of smooth and efficient functioning of the software. Thus, the database is a collection of information which is coherent and vital.