Depends whether each column has a separate index on it, or all columns are
in a single concatenated index.  An IOT is like the latter - it's only going
to help if you are always using the same (or similar) access path.  

Oracle doesn't go to a table if it can get all the values it needs from an
index.  So, I suspect that the performance of an IOT may not be any better
than a suitable concatenated index.  It simply saves you from storing the
data twice.

> -----Original Message-----
> From: Kimberly Smith [mailto:[EMAIL PROTECTED]]
> Sent: 24 October 2001 18:55
> To: Multiple recipients of list ORACLE-L
> Subject: Weirdness
> 
> 
> Oracle 8.1.7.1 on HPUX 11 
> 
> I have a table that I have just indexed every column.  This 
> has improved the
> query performance however, its going to slow down the load.  
> Thing that has
> me confused is that I tried this as an IOT and it actually 
> hurt performance.
> This table is joined to another table 3xs.  The table I made 
> an IOT has >2
> million rows and the other table has >6 million rows.  
> Shouldn't the IOT
> table have had similar performance to having every column indexed?
> 
> 
> 
> ________________________________________
> Kimberly Smith
> GMD Fujitsu
> Database Administrator
> (503) 669-6050
> 
> -- 
> Please see the official ORACLE-L FAQ: http://www.orafaq.com
> -- 
> Author: Kimberly Smith
>   INET: [EMAIL PROTECTED]
> 
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