Re: NESTED_TABLE_GET_REFS hint

The Metalink description of this hint seems a little obscure. My experience is that it simply allows you to reference a nested
table directly without 'pseudo-joining' it to its rightful parent.

Given the funny games (such as using
a thoroughly spurious /*+ cardinality() */ hint, and bypassing the constraint on
updateable join views) that Oracle plays for its internal purposes, I wouldn't
be surprised to see them "cheating" like this on MV updates as well. It doesn't
necessarily mean anything.

Regards

Jonathan Lewis
http://www.jlcomp.demon.co.uk

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

• Original Message ----- To: "Multiple recipients of list ORACLE-L" <ORACLE-L_at_fatcity.com> Sent: 13 March 2003 20:18

Hi,

I'm currently defining an optimization strategy for a reporting environment.
The reporting environment is refreshing 41 materialized views on a weekly
basis.
Some of the MV take over an 1 hour to refresh.

During the MV refresh, in Statspack, I can see that the top SQL are Oracle
generated SQL using the NESTED_TABLE_GET_REFS hint.

>From metalink : "If this is a DSS system, you probably have a smaller shared
pool and use import/export heavily. If so,it might be a good idea to use a
bigger shared pool when doing this activity."

Anyone has more info on this.

TIA Stephane Paquette
Administrateur de bases de donnees

Database Administrator

Standard Life

www.standardlife.ca

Tél. (514) 925-7187

stephane.paquette_at_standardlife.ca

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