Database Administration Questions

Light year is the unit of to express astronomical distances, that light can travel in one year. Light moves at a velocity of about 300,000 kilometers (km) each second. So in one year, it can travel about 10 trillion km. More precisely, one light-year is equal to 9,500,000,000,000 kilometers.

Approximately, 1 light year = 10^16 mts.

Let the number be 3p and 5p

ATQ,

8p = 2 x 48

p = 96/8

p = 12

The numbers are 36 and 60.

Hence, the product of the numbers = 36 x 60 = 2160.

RAM storage capacity is measured in bytes, kilo bytes, mega bytes, giga bytes,...

A clipboard is a temporary storage area for items that the user wants to cut or copy from one place to another.

For example, in a word processor application, the user might want to cut text from one part of a document and paste it in another part of the document or somewhere else, it is temporarily stored in clipboard.

IEEE 1284 is a standard that govern parallel communications.

• IEEE 1284 is a standard that defines bi-directional parallel communications between computers and other devices.

• It was originally developed in the 1970s by Centronics, and was widely known as the Centronics port, both before and after its IEEE standardization.

Internet service providers (ISP's) emerged in the late 1980's and early 1990's.

The ARPANET was decommissioned in 1990.

By 1995, the Internet was fully commercialized in the U.S., when the NSFNet was decommissioned, removing the last restrictions on use of the Internet to carry commercial traffic.

Candidate Key – A Candidate Key can be any column or a combination of columns that can qualify as unique key in database. There can be multiple Candidate Keys in one table. Each Candidate Key can qualify as Primary Key. 

Primary Key – A Primary Key is a column or a combination of columns that uniquely identify a record. Only one Candidate Key can be Primary Key.

• One needs to be very careful in selecting the Primary Key as an incorrect selection can adversely impact the database architect and future normalization. For a Candidate Key to qualify as a Primary Key, it should be Non-NULL and unique in any domain.

Passive Voice : Has the work been completed by him?

Rules in changing from Active voice to Passive voice :

1. Identify the subject, the verb and the object: S+V+O

2. Change the object into subject

3. Put the suitable helping verb or auxiliary verb

4. Change the verb into past participle of the verb

5. Add the preposition "by"

6. Change the subject into object.