Message-Id: <10711.124730@fatcity.com> From: Alex Hillman Date: Fri, 15 Dec 2000 12:53:35 -0500 Subject: RE: IOT Vs Normal Tables This message is in MIME format. Since your mail reader does not understand this format, some or all of this message may not be legible. ------_=_NextPart_001_01C066BF.F232DA70 Content-Type: text/plain; charset="iso-8859-1" You will not need any extra I/O if index contain all columns to satisfy your query. I know several people used IOT and they hadn't any performance improvement, only storage savings. Alex Hillman -----Original Message----- From: Murali Vallath [mailto:murali_vallath@hotmail.com] Sent: Friday, December 15, 2000 10:31 AM To: Multiple recipients of list ORACLE-L Subject: Re: IOT Vs Normal Tables Jared, Since the index and data are stored together, my impression on this subject was IOT's will save you the extra I/O for the data lookup. With the B-TREE index structure being common, the savings should be in the data lookup. Also, from the Oracle Internals class I had the opportunity to attend in October, at Hustone TX, the instructor told us that with 9i the data dictionary will be using IOT. I have not tested it myself, but these are from training, conversations and reading knowledge. Murali Vallath Oracle Certified DBA http://www8.ewebcity.com/muralivallath http://www.summerksyus.com/ Reply-To: ORACLE-L@fatcity.com To: Multiple recipients of list ORACLE-L Date: Wed, 13 Dec 2000 20:35:31 -0800 On Wed, 13 Dec 2000, Sanjay Kumar wrote: > Hi, > > Can anyone tell me how to see the performance differences of using IOTs over the normal tables. > > Sanjay > I don't think you will see any performance increase from an IOT. You can get the same performance if your query can be satisfied by an index without reading the table. i.e. the index has all the columns to satisfy the query. IOT's just save space and complicate your life. :) Jared Still Certified Oracle DBA and Part Time Perl Evangelist ;) jkstill@teleport.com jared_still@enron.net -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: jared still INET: jkstill@teleport.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@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). _________________________________________________________________ Get your FREE download of MSN Explorer at http://explorer.msn.com -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: Murali Vallath INET: murali_vallath@hotmail.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@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). ------_=_NextPart_001_01C066BF.F232DA70 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable RE: IOT Vs Normal Tables

You will not need any extra I/O if index contain all = columns to satisfy your query. I know several people used IOT and they = hadn't any performance improvement, only storage savings.

Alex Hillman

-----Original Message-----
From: Murali Vallath [mailto:murali_vallath@hotmail= .com]
Sent: Friday, December 15, 2000 10:31 AM
To: Multiple recipients of list ORACLE-L
Subject: Re: IOT Vs Normal Tables


Jared,

Since the index and data are stored together, my = impression on this subject
was IOT's will save you the extra I/O for the data = lookup.

With the B-TREE index structure being common, the = savings should be in the
data lookup.

Also, from the Oracle Internals class I had the = opportunity to attend in
October, at Hustone TX, the instructor told us that = with 9i the data
dictionary will be using IOT.

I have not tested it myself, but these are from = training, conversations and
reading knowledge.

Murali Vallath
Oracle Certified DBA
http://www8.ewebcity.com/muralivallath
http://www.summerksyus.com/

Reply-To: ORACLE-L@fatcity.com
To: Multiple recipients of list ORACLE-L = <ORACLE-L@fatcity.com>
Date: Wed, 13 Dec 2000 20:35:31 -0800

On Wed, 13 Dec 2000, Sanjay Kumar wrote:

 > Hi,
 >
 > Can anyone tell me how to see the = performance differences of using IOTs
over the normal tables.
 >
 > Sanjay
 >

I don't think you will see any performance = increase
from an IOT.

You can get the same performance if your query = can
be satisfied by an index without reading the = table.
i.e. the index has all the columns to satisfy the = query.

IOT's just save space and complicate your life. = :)

Jared Still
Certified Oracle DBA and Part Time Perl Evangelist = ;)
jkstill@teleport.com
jared_still@enron.net

--
Please see the official ORACLE-L FAQ: http://www.orafaq.com
--
Author: jared still
   INET: jkstill@teleport.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@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).

_______________________________________________________________= __
Get your FREE download of MSN Explorer at http://explorer.msn.com

--
Please see the official ORACLE-L FAQ: http://www.orafaq.com
--
Author: Murali Vallath
  INET: murali_vallath@hotmail.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@fatcity.com (note EXACT spelling of = 'ListGuru') and in
the message BODY, include a line containing: UNSUB = ORACLE-L