redundant indices?

From: ryan <ryanbobko_at_yahoo.com>
Date: 2 Oct 2003 07:21:37 -0700
Message-ID: <29c46df8.0310020621.788b9c2f@posting.google.com>

Hi All,
I've been reviewing some indices in a database I've recently become the DBA for, and I need some advice. On one table, we have the following indices (the names have been changed to protect the innocent):

index1( AAA, XXX, YYY );
index2( BBB, XXX, YYY );
index3( XXX, YYY, ZZZ );
index4( CCC, YYY, ZZZ );
index5( DDD, YYY, ZZZ );

I'm a bit less concerned with speed than I am disk space, and I was wondering if the following layout wouldn't be appropriate:

index6( YYY, ZZZ );
index7( XXX, YYY );
index8( AAA );
index9( BBB );

index10( CCC );
index11( DDD );

I guess my question is: Can oracle approximate the performance of index1 by searching index8 and combining the results with a search of index7? Or will only index8 be used?

Thanks for the advice,
ry Received on Thu Oct 02 2003 - 09:21:37 CDT