Oracle FAQ Your Portal to the Oracle Knowledge Grid
HOME | ASK QUESTION | ADD INFO | SEARCH | E-MAIL US
 

Home -> Community -> Mailing Lists -> Oracle-L -> Re: Rebuilding Indexes...

Re: Rebuilding Indexes...

From: Jared Still <jkstill_at_cybcon.com>
Date: Mon, 30 Dec 2002 15:23:39 -0800
Message-ID: <F001.005246BD.20021230152339@fatcity.com>

Ditto.

Conner did a better job of stating
it than I was going to. :)

Jared

On Monday 30 December 2002 11:08, Connor McDonald wrote:
> The space saving is good if you are not planning on
> doing much more with those indexes (ie dml). The
> space saving might be very very bad if there is lots
> of dml to come.
>
> If you're indexes reached "equilibrium" during normal
> operation of (say) 70% used, and then you rebuild them
> with (say) pctfree 10, they pop up to 90% used and
> thus the saved space. But if normal operations
> continue, they will eventually drift out to 70% used
> again and what's worse, you might get a bucketload of
> index block splits during the process...could be a
> nasty hit on dml performance
>
> hth
> connor
>
> --- John.Dailey_at_ing-fsi-na.com wrote: >
>
> > Jared, thanks for the "asktom" article, very
> > interesting reading - I'm not
> > 100% sure I agree with him though. I just
> > recently went through the
> > exercise to rebuild our indexes into locally-managed
> > tablespaces and I
> > saved over 100GB of space through the rebuild
> > process - as an example I had
> > a 51GB unique index that went to 30GB after the
> > rebuild (I'm not implying
> > locally-managed had anything to do with the space
> > savings, that was just
> > for reducing/eliminating fragmentation). The
> > indexes had not been
> > rebuilt in over a year. Our DSS database is
> > next; I expect to save at
> > least that plus more in space. Not to discount
> > Tom's arguments but I was
> > very happy with the space savings and depending on
> > your environment that
> > can be very helpful/worthwhile.
> >
> > Just my opinion - guess it depends on your
> > objectives. This
> > discussion has definitely got me thinking in some
> > different directions
> > which is always a good thing.
> >
> > thanks again,
> >
> > John D.
> > Atlanta, GA
> >
> >
> >
> >
> >
> >
> >
> >
> >
> > "Jared Still"
> >
> >
> > <jkstill_at_cybcon.c To:
> > "Multiple recipients of list ORACLE-L"
> > <ORACLE-L_at_fatcity.com>
> > om> cc:
> > (bcc: John Dailey/NAC/ING-FSI-NA)
> >
> > Sent by:
> > Subject: Re: Rebuilding Indexes...
> >
> > root_at_fatcity.com
> >
> >
> >
> >
> >
> >
> >
> >
> > 12/26/2002 10:13
> >
> >
> > PM
> >
> >
> > Please respond to
> >
> >
> > ORACLE-L
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> > Though I have published a script for determining
> > indexes that
> > need to be rebuilt, and then rebuilding them, I
> > have to say that
> > this is almost never necessary.
> >
> > Why are you rebuilding indexes? About the only
> > reason for ever
> > doing so is that the BLEVEL >= 5.
> >
> > goto asktom.oracle.com, and do a search on 'index
> > rebuild'.
> >
> > Currently, the third article may be of interest.
> >
> > Jared
> >
> > On Thursday 26 December 2002 12:24, Richard Huntley
> >
> > wrote:
> > > Anyone have any useful scripts for doing this?
> > >
> > > TIA,
> > > Rich
> >
> > ----------------------------------------
> > Content-Type: text/html; charset="iso-8859-1";
> > name="Attachment: 1"
> > Content-Transfer-Encoding: 7bit
> > Content-Description:
> > ----------------------------------------
> > --
> > Please see the official ORACLE-L FAQ:
> > http://www.orafaq.net
> > --
> > Author: Jared Still
> > INET: jkstill_at_cybcon.com
> >
> > Fat City Network Services -- 858-538-5051
> > http://www.fatcity.com
> > San Diego, California -- Mailing list and web
> > hosting services
>
> ---------------------------------------------------------------------
>
> > 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.net
> > --
> > Author:
> > INET: John.Dailey_at_ing-fsi-na.com
> >
> > Fat City Network Services -- 858-538-5051
> > http://www.fatcity.com
> > San Diego, California -- Mailing list and web
> > hosting services
>
> ---------------------------------------------------------------------
>
> > 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).
>
> =====
> Connor McDonald
> http://www.oracledba.co.uk
> http://www.oaktable.net
>
> "GIVE a man a fish and he will eat for a day. But TEACH him how to fish,
> and...he will sit in a boat and drink beer all day"
>
> __________________________________________________
> Do You Yahoo!?
> Everything you'll ever need on one web page
> from News and Sport to Email and Music Charts
> http://uk.my.yahoo.com

-- 
Please see the official ORACLE-L FAQ: http://www.orafaq.net
-- 
Author: Jared Still
  INET: jkstill_at_cybcon.com

Fat City Network Services    -- 858-538-5051 http://www.fatcity.com
San Diego, California        -- Mailing list and web hosting services
---------------------------------------------------------------------
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 Mon Dec 30 2002 - 17:23:39 CST

Original text of this message

HOME | ASK QUESTION | ADD INFO | SEARCH | E-MAIL US