Re: Oracle 11g - Invisible Indexes

Robert,

I got your point. However this same feature is already available in the form of NOSEGMENT indexes where you can create an index (with NOSEGMENT) and try the index using a little known undocumented parameter (_use_nosegment_indexes=true) at session level. We do that all the time before trying an index.

I just see this as an extension of nosegment indexes..

-Gopal

On 8/20/07, Robert Freeman <robertgfreeman_at_yahoo.com> wrote:
> I rather suspect where Oracle is going with the
> invisible index is associated with the automated SQL
> tuning. Say, for example, Oracle reviews SQL that has
> run and determines that an index would benefit the
> execution plan. Why not create it as an invisible
> index (thus, you don't impact other execution plans),
> test it and quantify the performance and then, if you
> get say 3 or 4x performance, you make it visible.

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Best Regards,
K Gopalakrishnan
Co-Author: Oracle Wait Interface, Oracle Press 2004
http://www.amazon.com/exec/obidos/tg/detail/-/007222729X/

Author: Oracle Database 10g RAC Handbook, Oracle Press 2006
http://www.amazon.com/gp/product/007146509X/
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