3i Infotech Papers: Sample Questions 654 - 655 of 1245

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Question number: 654

» Operating System » Unix

Short Answer Question▾

Write in Short

What are the phases of swapping a page from the memory?

Explanation

Define swapping

Define Swapping

Define swapping

  • The eligibility for swapping a page is found by the page stealer which puts the eligible pages in a list of pages.

  • The page is copied by the kernel to a swap device and the valid bit in the page table entry is cleared.

  • The data reference count is also decremented and the data table entry is placed at the end of the free list in case its reference count is 0.

Question number: 655

» Database » Oracle

MCQ▾

Question

Sequence of events takes place while starting a database is

Choices

Choice (4) Response

a.

Database opened, instance started, and file mounted

b.

Files mounted, instance started, & database opened

c.

Database opened, file mounted, and instance started

d.

Instance started, database mounted, and database opened

Answer

d.

Explanation

Steps of sequence of events take place starting database

Steps of Sequence of Events Take Place Starting Database

Steps of sequence of events take place starting database

Instance started

We perform preliminary steps before attempting to start an instance of database using SQL * Plus.

1. Start SQL * Plus without connecting to the database:

SQLPLUS/NOLOG

2. Connect to oracle as SYSDBA:

CONNECT username/password AS SYSDBA.

We are connected to oracle and ready to start up an instance of database.

Database mounted:

  • Some forms of recovery require that the database be opened in mount stage.

  • To put the database in mount stage, use the startup mount command:

    SQL > startup mount

  • We have started the database instance with the startup nomount command, we might change it from the nomount to mount startup stage using the database command:

    SQL > alter database mount

Database Opened:

  • We just use the startup command:

    SQL > tartup

  • If database is mounted, we can open it with the alter database open command:

    SQL > alter database open;