Saturday, 9 March 2013

Define the following terms. i. Database ii. Database Management System iii. Data Model iv. Schema v. Data Independence

Database:

A collection of related information stored in a structured format. Database is often used interchangeably with the term table (Lotus Approach, for instance, uses the term database instead of table). Technically, they're different: A table is a single store of related information; a database can consist of one or more tables of information that are related in some way. For instance, you could track all the information about the students in a school in a students table. If you then created separate tables containing details about teachers, classes and classrooms, you could combine all four tables into a timetabling database. Such a multi-table database is called a relational database..

What are the Roles and Responsibilities of database administrator?

The Database Administrator (DBA) is the super-user of the system.
The role of the DBA is very important and is defined by the following functions.

Ø  Defining the Schema
The DBA defines the schema which contains the structure of the data in the application. The DBA determines what data needs to be present in the system and how this data has to be represented and organized.

Describe the different number representations

Number Representations

Computers are built using logic circuits that operate on information represented by two valued electrical signals. We label the two values as 0 and 1; and we define the amount of information represented by such a signal as a bit of information, where bit stands for binary digit. The most natural way to represent a number in a computer system is by a string of bits, called a binary number. A text character can also be represented by a string of bits called a character code.

Friday, 8 March 2013

Implement the following basic operations on double ended queues: a) Insertion at the rear end b) Insertion at the front end


a) insertion at the rear end on a double ended queue
/*function to insert an item at the rear end on a double ended queue*/
void insert_rear(int item, int q[], int *r)
{
     if (qfull(*r))/*check if queue is full*/
     {
          printf(“Queue Overflow\n”);
     }
     /*queue is not full*/
     q[++(*r)]= item;
}

Wednesday, 6 March 2013