RE: a explain plan question

> 4 2 PARTITION RANGE (ITERATOR)
> 5 4 TABLE ACCESS (FULL) OF 'TUH_NVPAGINA' (Cost=27159

Means that Oracle are using some partitions, and then are doing a full scan of these partitions.  

Alex, I think you must create an LOCAL partitioned index on TUH_NVPAGINA.FE_DIA.   If you have more columns that FE_DIA in your primary key, Oracle may not use it.    

You need some like this:

2    1     PARTITION RANGE (ITERATOR)
3    2       INDEX (RANGE SCAN) OF 'TUH_NVPAGINA_IDX1' (INDEX) 

 

 

greetings  

De: oracle-l-bounce_at_freelists.org [mailto:oracle-l-bounce_at_freelists.org] En nombre de Polarski, Bernard
Enviado el: miércoles, 31 de enero de 2007 10:24 Para: ax.mount_at_gmail.com; oracle-l_at_freelists.org Asunto: RE: a explain plan question  

Still I don’t understand why we have a PARTITION RAND followed by a full table scan. Why not a direct full table scan, what is the advantage of this construct  

> 4 2 PARTITION RANGE (ITERATOR)
> 5 4 TABLE ACCESS (FULL) OF 'TUH_NVPAGINA' (Cost=27159

“

On 1/30/07, LS Cheng < exriscer_at_gmail.com> wrote:

TUD_FEDIA is accessed first then from that it eliminates partitions (partition start/stop KEY), the problem seems nested loop, how many rows is TU_FEDIA returning?
“  

I don’t see the keyword(stop key) in the plan. I read this plan and its only speak of a partition range access that leads to a full table scan.

My only explanation is that the CBO is underlining a failed partition pruning.  

Bernard Polarski

From: amonte [mailto:ax.mount_at_gmail.com] Sent: woensdag 31 januari 2007 10:09
To: oracle-l_at_freelists.org
Subject: Re: a explain plan question  

You are correct, the NL is not good, I changed to hash join and the query runs in 50 minutes.

Thanks

Alex

On 1/30/07, LS Cheng < exriscer_at_gmail.com> wrote:

doesnt look very good plan

TUD_FEDIA is accessed first then from that it eliminates partitions (partition start/stop KEY), the problem seems nested loop, how many rows is TU_FEDIA returning?

On 1/30/07, Remigiusz Soko?owski < rems_at_wp-sa.pl <mailto:rems_at_wp-sa.pl> > wrote:

>
> Execution Plan
> ----------------------------------------------------------
> 0 SELECT STATEMENT Optimizer=CHOOSE (Cost=1022392 Card=934
> Bytes=49502)
> 1 0 SORT (GROUP BY) (Cost=1022392 Card=934 Bytes=49502)
> 2 1 NESTED LOOPS (Cost=814767 Card=182275095 Bytes=9660580035)
> 3 2 TABLE ACCESS (FULL) OF 'TUD_FEDIA' (Cost=3 Card=30
> Bytes=480)
> 4 2 PARTITION RANGE (ITERATOR)
> 5 4 TABLE ACCESS (FULL) OF 'TUH_NVPAGINA' (Cost=27159
> Card=5992606 Bytes=221726422)
>
> I was wondering how to read this plan, the order of steps. From old
> set autotrace trace exp it seems to me that step 5 is the first step?
>
> 5 4 TABLE ACCESS (FULL) OF 'TUH_NVPAGINA' (Cost=27159
> Card=5992606 Bytes=221726422)
>

AFAIK the first most nested line is the first line (in this example the one indicated by You)

Regards
Remigiusz

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