Oracle FAQs for beginners

Oracle FAQs for beginners

When beginners are new to oracle, they will encounter two major questions: first, index range scan, and second, index unique scan ), the following two questions are illustrated in detail:

1. index range scan)

Copy codeThe Code is as follows:
Select empno, ename from emp where empno> 1 orderby empno

In this case, the index range scan is not used?

2. unique index scan)

When the data types are inconsistent, the unique index scan is not performed, but the unique index is still used.

Copy codeThe Code is as follows:
Select empno, ename from emp where empno = '10'

The above is a detailed explanation of common oracle questions for beginners. I hope you will like it.