Difference between INLINE view and WITH clause

Question

Can anyone plz explain me about the performance difference between the below queries?
Query using INLINE view:
SELECT e.ename AS employee_name,
dc.dept_count AS emp_dept_count
FROM emp e,
(SELECT deptno, COUNT(*) AS dept_count
FROM emp
GROUP BY deptno) dc
WHERE e.deptno = dc.deptno;
Query using WITH clause:
WITH dept_count AS (
SELECT deptno, COUNT(*) AS dept_count
FROM emp
GROUP BY deptno)
SELECT e.ename AS employee_name,
dc.dept_count AS emp_dept_count
FROM emp e,
dept_count dc
WHERE e.deptno = dc.deptno;

Answer 1

Here's another one:
http://www.oracle-base.com/articles/misc/WithClause.php
And, here on this forum you will see that the WITH-clause is heavily used by all of us in order to generate some sample data (when OP's don't care to post CREATE TABLE + INSERT INTO statements).
The WITH clause enables you as well to 'pretend' you have a table and demonstrate a solution very quickly, without doing actual DDL .
As for the performance difference:
We would need to know your database version and many other things.
See:
HOW TO: Post a SQL statement tuning request - template posting
for step by step instructions you can (and should) explore yourself.