RE: unexpected query plan

From: Polarski, Bernard <Bernard.Polarski_at_atosorigin.com>
Date: Tue, 23 Jan 2007 08:39:14 +0100
Message-ID: <25D4919915CCF742A88EE3366D6D913D117EA3AA@mailserver1>

The link is broken for me. Nevertheless for those interested in the subject here is a good resource from W. Breitling that explain it: http://www.centrexcc.com/What%20is%20new%20in%20the%20Oracle%209i%20CBO. ppt.pdf

Bernard Polarski
Oracle DBA

-----Original Message-----
From: Christian Antognini [mailto:Christian.Antognini_at_trivadis.com]

Paul

> What is this indexjoin operation?

To save a table access the query optimizer is able to get the data by joining two indexes on the same table (based on the ROWID that can be found in both segments). Of course this is only possible when all referenced attributes are indexed.

> I have never seen it.

FYI: this is not something "new". Here a link to the 8.1.5 where it is documented...
http://download-uk.oracle.com/docs/cd/F49540_01/DOC/server.815/a67781/c2 0b_ops.htm#1164

--
http://www.freelists.org/webpage/oracle-l

Received on Tue Jan 23 2007 - 01:39:14 CST