Re: a explain plan question


To answer the original question about how to identify
the first operation that could be considered for execution,
Dan Fink's answer is an excellent explanation - but for an
easier mechanism, I've just posted something about it on
my blog at

   http://jonathanlewis.wordpress.com/all-postings

In fact, Dan's answer needs a little corollary - as a plan
can contain conditional execution paths:
   http://jonathanlewis.wordpress.com/2007/01/09/conditional-sql/
so his comment needs a further messy expression wrapped around it discussing the possibility of when an entire subplan 
may or may not be executed at run-time.


Regards

Jonathan Lewis
http://jonathanlewis.wordpress.com

Author: Cost Based Oracle: Fundamentals
http://www.jlcomp.demon.co.uk/cbo_book/ind_book.html

The Co-operative Oracle Users' FAQ
http://www.jlcomp.demon.co.uk/faq/ind_faq.html
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------------------------------

Date: Tue, 30 Jan 2007 15:43:31 +0100
From: amonte <ax.mount@xxxxxxxxx>
Subject: a explain plan question

Hi
I have this query

SELECT
  TUH_NVPAGINA.ID_SECCION AS ID_SECCION,
  TUD_FEDIA.ID_TIPO_DIA AS ID_TIPO_DIA,
  TUD_FEDIA.ID_MES AS ID_MES,
  count(distinct TUH_NVPAGINA.TX_COOKIE_SESION) CNT
FROM
  TUH_NVPAGINA,
  (SELECT FE_DIA, ID_MES, ID_TIPO_DIA
     FROM TUD_FEDIA
    WHERE ID_MES = :p_f_inicio) TUD_FEDIA
WHERE TUH_NVPAGINA.FE_DIA = TUD_FEDIA.FE_DIA
GROUP BY
  TUH_NVPAGINA.ID_SECCION,
  TUD_FEDIA.ID_TIPO_DIA,
  TUD_FEDIA.ID_MES



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