Questions

1.Hardware abstraction layer

2.Kernel

3.Subsystems

4.System Services.

Euclid of Alexandria was a Greek mathematician, often referred to as the Father of Geometry.

The Indian Institute of Technology (IIT) Kanpur will confer a doctorate on former sprint queen PT Usha, who missed a medal by a whisker at the 1984, Los Angeles Olympics. The degree, Doctor of Science (honoris causa – a degree awarded as a mark of esteem) will be conferred on June 16 to mark the 50th convocation of the prestigious institute of the country. This is her second doctorate – in 2002, Kannur University had conferred D.Lit on her.

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.

The Length of the Day is determined in Astronomical Units.

The length of a day corresponds to the time the Earth takes to turn around on its axis, which is approximately 24 hours. But it's not exactly 24 hours. 

This phenomenon is due to tides raised by the Moon which slow Earth's rotation. Because of the way the second is defined, the mean length of a day is now about 86 400.002 seconds, and is increasing by about 1.7 milliseconds per century.