3i Infotech Papers: Sample Questions 453 - 455 of 1245

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

Question number: 453

» Database » MySQL

Essay Question▾

Describe in Detail

What is RDBMS KERNEL?

Explanation

  • A relational database management system (RDBMS) is a program that lets you create, update, and administer a relational database.

  • Use of the Structured Query Language (SQL) to access the database, SQL was invented after the development of the relational model and is not necessary for its use.

  • The software and the data dictionary is the two important pieces of RDBMS architecture are the kernel, which consists of the system-level data structures to manage the database used by the kernel.

  • An RDBMS maintains its own list of authorized users and their associated privileges;

    • manages memory caches and paging

    • controls locking for concurrent resource usage

    • dispatches and schedules user requests

  • Sub-systems of a RDBMS:

    • I/O

    • Security

    • Language ProcessingProcess Control

    • Storage Management

    • Logging and Recovery

    • Distribution Control

    • Transaction Control

    • Memory Management

    • Lock Management

Question number: 454

» Database » Oracle

MCQ▾

Question

SYSTEM. EFFECTIVE. DATE variable is

Choices

Choice (4) Response

a.

Read only

b.

Write only

c.

Read & Write

d.

All of the above

Answer

b.

Explanation

  • The SYSTEM. EFFECTIVE. DATE variable is write only.

  • Enables to set the effective database date.

Question number: 455

» Operating System » Unix

Essay Question▾

Describe in Detail

Explain fork () system call.

Explanation

Chart of parent, fork and child

Chart of Parent, Fork and Child

Chart of parent, fork and child

  • System call fork () is used to create processes.

  • Takes no arguments and returns a process ID.

  • Creates a new process- becomes the child process of the caller.

  • After child of child instructions in fork () are executed.

Fork

  • Returns a negative value, if the child process creation is unsuccessful.

  • Returns positive value containing the ‘process id’, to the parent.

Process ID

  • An integer identifying a process

  • getpid () retrieves the process ID assigned to the process.

  • After system call to fork (), a simple test can identify the child.