Re: Strange cost difference

From: Mladen Gogala <no_at_email.here.invalid>
Date: Thu, 17 Feb 2011 23:02:14 +0000 (UTC)
Message-ID: <pan.2011.02.17.23.02.14_at_email.here.invalid>



On Thu, 17 Feb 2011 22:34:02 +0000, Mladen Gogala wrote:

> The question is why does oracle think that this statement will return 15
> rows?

I figured it out. The recursive CTE has 2 parts: the initial and the recursive part. The part of the 1st statement which says

"select empno,mgr,1 from emp where empno=7839"

plays the same role as the "start with empnp=7839" part of the "connect by" version, but is apparently executed separately. It seems to me that the good, old "connect by" stuff is still preferred by Oracle.

-- 
http://mgogala.byethost5.com
Received on Thu Feb 17 2011 - 17:02:14 CST

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