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: bitmap index Q.

RE: bitmap index Q.

From: Jared Still <jkstill_at_bcbso.com>
Date: Mon, 1 May 2000 09:42:37 -0700 (PDT)
Message-Id: <10484.104565@fatcity.com>


Hmm... That sounds like a good exercise.

Time to break out the 'Data Structures' book, and put it in the queue with the other 20 or so books I'm supposed to read.

Jared

On Mon, 1 May 2000, I.S. Manager wrote:

> Automatic tree-balancing is a basic feature of the btree algorithm. I wrote
> a btree function once just to get a feel for what it does, and I can tell
> you that it makes absolutely no difference whether the keys go in in
> sequential, reverse-sequential, or random order.
>
>
> At 02:49 PM 4/28/00 -0800, Jain, Akshay wrote:
> >Is it true that if data is loaded in *sequential* order, with indexing on,
> >the index gets lop sided. Thus only rebuilding the index(es) can
> >restore its beneficial, shallow and wide structure.
> >
> >Unless there is automatic tree-balancing for indexes that Oracle
> >does by itself?
> >
> >Akshay Jain
> >_______________________
> >Newcourt-CIT
> >Tel. (416) 507-5385
> >mailto:Akshay.Jain_at_cit.com
> >_______________________
> >
> >
> >-----Original Message-----
> >Sent: Friday, April 28, 2000 3:54 PM
> >To: Multiple recipients of list ORACLE-L
> >
> >
> >Hola!
> >
> >One of our data marts here had awful performance yesterday. The only thing
> >that
> >was different between yesterday and the previous days was that the load ran
> >with
> >all indexes, including bitmaps, on the tables. Only 10,000 rows were added
> >-
> >less than 1% change. The analyze was run for all tables to be hit by the
> >reports. However performance really bit yesterday until the indexes were
> >dropped and rebuilt.
> >
> >In class I remember talking about the tradeoff between a fast load/building
> >indexes and a slow load/leaving indexes up. Has anyone seen this type of
> >behavior before? I can not say for sure that the load is not updating the
> >fields the bitmap indexes were on.
> >
> >Any comments are appreciated.
> >
> >Lisa 'Almost Certified' Koivu
> >
> >
> >
> >--
> >Author:
> > INET: Lisa_Koivu_at_gelco.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).
> >--
> >Author: Jain, Akshay
> > INET: Akshay.Jain_at_cit.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).
> >
> >
> ---
> Dennis Taylor
> ---
> The opinions expressed herein are mine. Get your own opinions!
> ---
> --
> Author: I.S. Manager
> INET: ismgr_at_pctc.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).
>

Jared Still
Certified Oracle DBA and Part Time Perl Evangelist ;-) Regence BlueCross BlueShield of Oregon Received on Mon May 01 2000 - 11:42:37 CDT

Original text of this message

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