Sunday, May 18, 2014

Oracle query optimization tips

Query optimization tips :-

1.Rewrite complex subqueries with temporary tables.

2.Use minus instead of EXISTS subqueries

3.Use SQL analytic functions

4.Re-write NOT EXISTS and NOT EXISTS subqueries as outer joins

5. Index all the comparing columns in query

6.Avoid the use of NOT IN or HAVING

7.Avoid the LIKE predicate

8.Use decode and case

9.Always use table aliases when referencing columns

10.Never mix data types

No comments:

Post a Comment