RE: Hint for self-join connect by

From: Herring Dave - dherri <Dave.Herring_at_acxiom.com>
Date: Tue, 1 May 2007 11:47:54 -0500
Message-ID: <7ED53A68952D3B4C9540B4EFA5C76E360326B90F@CWYMSX04.Corp.Acxiom.net>

Got it:

Predicate Information (identified by operation id):

2 - filter("from$_subquery$_001"."RN"=1) 3 - filter(ROW_NUMBER() OVER ( PARTITION BY SUBSTR("from$_subquery$_003"."TREE",1,INSTR("from$_subquery$_003"."TREE" ,'|')-1)

ORDER BY "from$_subquery$_003"."LEV" DESC )<=1)

   4 - filter(INSTR("from$_subquery$_003"."TREE",'|')>0)
   5 - filter("DCH_WORK_SURR_MGMT_ONE"."ACCT_ID"='_MERGED_')
   6 - filter("DCH_WORK_SURR_MGMT_ONE"."ACCT_ID"='_MERGED_')

I haven't tried gathering at 100%, mostly because there are 70 million rows. I do plan on trying various histogram options on ACCT_ID.

As for the count of '_MERGED_' rows, its about 450,000.

Dave

David C. Herring, DBA | A c x i o m Delivery Center Organization

630-944-4762 office | 630-430-5988 wireless | 630-944-4989 fax

> -----Original Message-----
> From: Alberto Dell'Era [mailto:alberto.dellera_at_gmail.com]
> Sent: Tuesday, May 01, 2007 11:14 AM
> To: Herring Dave - dherri
> Cc: amit poddar; oracle-l
> Subject: Re: Hint for self-join connect by
>
> I think Amit was asking for the "filter predicates" section at the
> end of the explain plan ;)
>
> By the way, have you tried collecting statistics at 100%, to see
> whether that makes any difference ?
>
> How many rows (starting rows) with acct_id = '_MERGED_' there are
> in the tables - a few, many, almost all ?

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Received on Tue May 01 2007 - 11:47:54 CDT