3i Infotech Papers: Sample Questions 359 - 362 of 1245

Examrace Placement Series prepares you for the toughest placement exams to top companies.

Question number: 359

» Operating System » Unix

Short Answer Question▾

Write in Short

What is a Region?

Explanation

  • A region is a continuous area of a process’s address space.

  • Kernel maintains region table in memory local to the process.

  • Regions are sharable among the process.

Question number: 360

» Basic CS » Networks

Short Answer Question▾

Write in Short

What are Diagram and Trigrams?

Explanation

Diagram:

  • Common two letter combinations are called as diagrams

  • Example: th, in, er, re and an.

Trigrams:

  • Common three letter combinations are called as trigrams.

  • Example: the, ing, and and ion.

Question number: 361

» Operating System » Unix

Short Answer Question▾

Write in Short

What is a Daemon?

Explanation

A daemon process:

  • Runs in the background and is independent of control from all terminals.

  • Comes up during boot-up and terminates when the system is rebooted.

  • Is not attached to a terminal like a foreground process.

  • Either created by a process by forking a child process and then immediately exiting, thus causing init to adopt the child process, or the init process directly launching the daemon.

  • Thus, in a unix environment, the parent process of a daemon is often, but not always, the init process.

  • The operating system typically performs other operations, dissociating the daemon process from any controlling terminal.

Question number: 362

» Database » MySQL

Essay Question▾

Describe in Detail

Describe the three levels of data abstraction?

Explanation

The three levels of data abstraction

The Three Levels of Data Abstraction

The three levels of data abstraction

Physical Level:

  • It is the lowest level of abstraction and describes how the data in the database are actually stored.

  • This level describes complex low-level data structures in detail and is concerned with the way the data is physically stored.

  • Data only exists at physical level.

Logical Level:

  • This is the next higher level of abstraction and describes what data are stored in the database, and what relationships exist among those data.

  • It describes the structure of whole database and hides details of physical storage structure.

  • It concentrates on describing entities, data types, relationships, attributes and constraints.

  • All of the views must be derivable from this conceptual schema.

View Level:

  • It is the highest level of abstraction and is concerned with the way the data is seen by individual users.

  • This level simplifies the users’ interaction with the system.

  • It includes a number of user views and hence is guided by the end user requirement.

  • It describes only those part of the database in which the users are interested and hides rest of all from those users.

  • Each user group refers to its own external schema.