3i Infotech Papers: Sample Questions 753 - 754 of 1245

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Question number: 753

» Operating System » Unix

Essay Question▾

Describe in Detail

What are conditions for a machine to support Demand Paging?


  • The process of mapping a large address space into a relatively small amount of physical memory is known as demand paging.

  • Demand paging is done by implementing ‘backing store’.

Condition Required for Demand Paging:

  • Page based memory architecture.

  • Restartable instructions supported by the machine.

  • To start process, load the code page where the process will start executing.

  • Process references memory outside of loaded page, bring in as necessary.

  • Only brings page into main memory when a reference is made to a location on the page.

  • The characteristic problem is that there are many page faults when process is first started.

Question number: 754

» Database » MySQL

Essay Question▾

Describe in Detail

What is a query?


Understanding of query languages.

Understanding of Query Languages.

Understanding of query languages.

  • A query is a request for data or information from a database table or combination of tables.

  • This data may be generated as results returned by Structured Query Language or as pictorials, graphs or complex results, e. g. , trend analyses from data-mining tools.

  • Query languages generates different data types according to function.

  • For example, SQL returns data in neat rows and columns and is very similar to Microsoft Excel in appearance.

  • Other query languages generate data as graphs or other complex data manipulations, e. g. , data mining, which is the deep analysis of information for unknown trends and relationships.