2. Analytical Function Ranking RANK, DENSE_RANK, CUME_DIST,
PERCENT_RANK,NTILE, ROW_NUMBER LAG and LEAD FIRST_VALUE and
LAST_VALUE FIRST and LAST Windowing Reporting Most of aggregate
function can be user (MAX, MIN, AVG,SUM, COUNT) 3. Ranking (RANK,
DENSE_RANK, CUME_DIST) 4. Ranking (PERCENT_RANK, NTILE, ROW_NUMBER)
5. LEAD and LAG 6. FIRST_VALUE and LAST VALUE 7. FIRST and LAST 8.
Windowing 9. Windowing (cont.) 10. Windowing (cont.) 11. Reporting
(RATIO_TO_REPORT) 12. Hypothetical Rank 13. Flashback Flashback
query Flashback version query Flashback transaction query Flashback
Table Flashback Drop 14. Flashback Query 15. Flashback Query
(cont.) 16. Flashback Version Query 17. Flashback Transaction Query
Query flashback_transaction_query view 18. Flashback Table Row
Movement should be enabled 19. Flashback Drop 20. Rewrite Query
Correlated Sub-QueryCheck logical I/O 21. Rewrite Query IN vs
EXISTS Not In and Not Exists will produces exactly the same result
ifthere is no NULL record in the sub-query. Extra predicate can be
added for NULL value checking. Not Exists is more efficient because
when Oracle found 1 record that satisfied the condition in the
Sub-Query, it will move to the next record of Main Query and also
Oracle will be able to use index in Sub-Query. In case of Not In,
Oracle has to scan whole population of SubQuery before it move to
the next record of Main Query. It will takes more IO and because of
implicit NVL function in the predicate, Oracle will not be able to
use index access. Not In will be translated as ((COL != VALUE_1)
AND (COL != VALUE_2) AND (COL != VALUE_3) AND (COL != VALUE_X)) 22.
Log Mining Collection of procedure to read an examine redo log
orarchive log Database Supplemental Log Data should be turn on.
