explain the ROLLUP, CUBE, RANK AND DENSE_RANK FUNCTIONS OF
ORACLE 8I
Answers were Sorted based on User's Feedback
Answer / vikram
Diff between RANK() and DENSE_RANK():-
------------*******-----************-------
RANK():-
---> It leaves a gap in the sequence of ranking in the
event of tie.
DENSE_RANK():-
---> It doesn't leave a gap in the sequence of ranking
in the event of tie.
EX:-
empno ename RANK DENSE_RANK
101 AAA 1 1
102 BBB 2 2
102 BBB 2 2
102 BBB 2 2
103 CCC -->5 --> 3
103 CCC 5 3
104 DDD -->7 --> 4
| Is This Answer Correct ? | 10 Yes | 0 No |
Answer / satya
ROLLUP is used to Calculate The subtotals And Grand Total
Based On The Groupby Function.
This ROLLUP is used after the GROUP BY function.
CUBE generates a result set that represents aggregates for
all combinations of values in the selected columns.
RANK Function Is Used To Give The Ranks,But It miss Some
Ranks When Both Are Getting Same Ranks.
DENSE_RANK function Won't Give The Gaps Between The Ranks.
| Is This Answer Correct ? | 8 Yes | 3 No |
Answer / friend
ROLL UP IS USED TO FIND THE SUB TOTALS ,IT IS USED AFTER
GROUP BY FUNCTION,AND"CUBE"IS ALSO HAVING THE SAME
MEANING,AND RANK FUNC IS USED TO FIND THE RANKS AND IT
GIVES THE SAME RANK IF DATA HAVING SAME DATA,AND DENSE
_RANK ALSO SAME AS RANK BUT IT WILL GIVE DISTINCT RANKS IF
AT ALL IF THE DATA HAVING SAME DATA.
| Is This Answer Correct ? | 8 Yes | 7 No |
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