Re: [Q] How oracle rebuild index internally?

From: Jonathan Lewis <jonathan_at_jlcomp.demon.co.uk>
Date: Thu, 1 Apr 2004 22:11:02 +0100
Message-ID: <011101c4182d$d85328a0$7102a8c0@Primary>

Technically, it's a cost-based decision.

For 'offline rebuilds the optimizer could choose to use the index or table. For online rebuilds it looks as if the optimizer HAS to use the table.

Just for information - could you explain what you mean by finding 'one index bad'. Was this an 'analyze validate structure', and what error message did it produce. Perhaps if you altered it to unusable you would be able to rebuild (from the table) without dropping.

Regards

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

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

April 2004 Iceland http://www.index.is/oracleday.php June 2004 UK - Optimising Oracle Seminar

Original Message ----- From: "dba1 mcc" <mccdba1_at_yahoo.com> To: <oracle-l_at_freelists.org>; <oracledba_at_lazydba.com> Sent: Thursday, April 01, 2004 9:52 PM Subject: [Q] How oracle rebuild index internally?

several days ago, I analyze my tables and indexes and found one index is bad. I use "alter index indexname rebuild;". ORACLE don't allow me to do it due to original index is bad. I wonder when ORACLE doing index rebuild it does NOT reread from table but reread from old index. Is it true?

The version we use is ORACLE 9ir2 (9.2.0.4).

Thanks.

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Received on Thu Apr 01 2004 - 15:25:20 CST