Does indexing a column which has different values for all rows makes sense?


#1

If a column takes different values for all rows of a table will it be a overhead to make that column indexed


#2

Generally columns with same values will be taken as index. We can have composite indexes but a the columns will have same values. They do not contain different values.


#3

Generally columns with same values will be taken as index. We can have composite indexes but they all have same values for their rows. If there are different values it will be difficult.