RE: How to do faster updates

From: Fink, Dan <Dan.Fink_at_mdx.com>
Date: Fri, 13 Sep 2002 12:23:24 -0800
Message-ID: <F001.004CFD32.20020913122324@fatcity.com>

I love being a contrarian...so here goes...

Are you certain you need an index? The time it will take to read the blocks to create an index (space management and full table scan?), analyze the index for the CBO (necessary?), perform the update, then drop the index. Is this amount of time going to be less than doing an update via a full table scan?

I agree with Jerry's 3rd sentence .. 'Make a copy of the table and see if an index helps or not.' That will prove it. Of course, that also takes time...

-----Original Message-----
From: Whittle Jerome Contr NCI [mailto:Jerome.Whittle@scott.af.mil]
Sent: Friday, September 13, 2002 12:48 PM
To: Multiple recipients of list ORACLE-L
Subject: RE: How to do faster updates

Rajesh,

Build an index. If this is something you will do often; and if that column is a good candidate for an index; and if the index wouldn't slow down inserts and updates too much; consider creating an index. Make a copy of the table and see if an index helps or not. If nothing else you could always create an index; do the updates; and drop the index.

Jerry Whittle
ACIFICS DBA
NCI Information Systems Inc.
jerome.whittle@scott.af.mil
618-622-4145

-----Original Message-----
From: Pillai, Rajesh [SMTP:Rajesh.Pillai@nordstrom.com]

Hi All,
I've a table of 10 M records and I want to update some thousand records based on a column which is not a part of any index. Please suggest the quickest way to do this.

Thanks,
Rajesh

-- 
Please see the official ORACLE-L FAQ: http://www.orafaq.com
-- 
Author: Fink, Dan
  INET: Dan.Fink_at_mdx.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 Fri Sep 13 2002 - 15:23:24 CDT