Explanation : In Unix, the command to enable execution permission for file “mylife” by all are: Chmod + X myfile Chmod a + X myfile Chmod ugo + X myfile So, option (D) is correct.
Explanation : $rm chap0\[1 - 3\] Square bracket surround a choice for single character and hyphen(-) will separate the range of single character. Above command will remove chap 01 or chap 02 or chap 03 file. So, option (A) is correct.
Explanation : Features of the object-oriented approach to databases: The ability to develop more realistic models of the real world. The ability to represent the world in a non-geometric way. The ability to develop databases using natural language approaches. So, option (A) is correct.
Explanation : check(one≥1 and ≤10),check(two≥1 and ≤5).
Here second constraint will decide the no of tuples(record). Or we can say that the common condition will dominate.
i.e. check(two ≥ 1 and ≤ 5) 5 tuples.
So, option (A) is correct.
Explanation : Full join will give two match for B = 2 and B = 4. and two mismatch So it will give 4 output. Inner join will give output for only matching condition. B = 2 and B = 4. Two output from inner join. So, option (D) is correct.