RE: Weirdness

From: Kimberly Smith <kimberly.smith_at_gmd.fujitsu.com>
Date: Thu, 25 Oct 2001 08:10:12 -0700
Message-ID: <F001.003B463B.20011025081558@fatcity.com>

Its one index with all the columns. This is why I was thinking it would be the same or similar performance. The execution path is fine and considering how many rows I am dealing with the execution is more then fine. I was trying to reduce storage and speed up the loads a bit.

-----Original Message-----
Sent: Thursday, October 25, 2001 1:40 AM To: Multiple recipients of list ORACLE-L

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:kimberly.smith_at_gmd.fujitsu.com]
> 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: kimberly.smith_at_gmd.fujitsu.com
>
> Fat City Network Services -- (858) 538-5051 FAX: (858) 538-5051
> San Diego, California -- Public Internet access / Mailing Lists
> --------------------------------------------------------------------
> To REMOVE yourself from this mailing list, send an E-Mail message
> to: ListGuru_at_fatcity.com (note EXACT spelling of 'ListGuru') and in
> the message BODY, include a line containing: UNSUB ORACLE-L
> (or the name of mailing list you want to be removed from). You may
> also send the HELP command for other information (like subscribing).
>

This message (including any attachments) is confidential and may be legally privileged. If you are not the intended recipient, you should not disclose, copy or use any part of it - please delete all copies immediately and notify the Hays Group Email Helpdesk at email.helpdesk_at_hays.plc.uk
Any information, statements or opinions contained in this message (including any attachments) are given by the author. They are not given on behalf of Hays unless subsequently confirmed by an individual other than the author who is duly authorised to represent Hays.

A member of the Hays plc group of companies. Hays plc is registered in England and Wales number 2150950. Registered Office Hays House Millmead Guildford Surrey GU2 4HJ.

-- 
Please see the official ORACLE-L FAQ: http://www.orafaq.com
-- 
Author: Lord, David - C&S
  INET: David.Lord_at_hayscsg.com

Fat City Network Services    -- (858) 538-5051  FAX: (858) 538-5051
San Diego, California        -- Public Internet access / Mailing Lists
--------------------------------------------------------------------
To REMOVE yourself from this mailing list, send an E-Mail message
to: ListGuru_at_fatcity.com (note EXACT spelling of 'ListGuru') and in
the message BODY, include a line containing: UNSUB ORACLE-L
(or the name of mailing list you want to be removed from).  You may
also send the HELP command for other information (like subscribing).
-- 
Please see the official ORACLE-L FAQ: http://www.orafaq.com
-- 
Author: Kimberly Smith
  INET: kimberly.smith_at_gmd.fujitsu.com

Fat City Network Services    -- (858) 538-5051  FAX: (858) 538-5051
San Diego, California        -- Public Internet access / Mailing Lists
--------------------------------------------------------------------
To REMOVE yourself from this mailing list, send an E-Mail message
to: ListGuru_at_fatcity.com (note EXACT spelling of 'ListGuru') and in
the message BODY, include a line containing: UNSUB ORACLE-L
(or the name of mailing list you want to be removed from).  You may
also send the HELP command for other information (like subscribing).

Received on Thu Oct 25 2001 - 10:10:12 CDT