Instead of using a NULL how do I show a "0" using a SELECT statement for a particular column?
Here is the answer.Use the coalesce function. SELECT coalesce (column,0) as column. coalesce function returns the first null value.
There are two vectors X<-c(3,2,4) and Y<-c(1,2) . What is the will be the result for Z<-X*Y?
The result is Z<-(3,4,4).In R when two vectors are of different length,multiplication begins with a smaller vector and continues till all the elements in the larger vector have been multiplied. So, the result is as such Z<- (3*1 , 2*2 , 4*1)
What is the disadvantage of using flat files foe storing the attribute information?
A lot of space gets wasted using a flat file, since every data record must contain the same number of fields regardless of the use of the field or not.This becomes a very big problem in large files containing lot of fields which do not have the same data field.In that case it becomes a big problem to store the data in such flat files.