RE: bitmap index Q.

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
>
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>Author: Jain, Akshay
> INET: Akshay.Jain_at_cit.com
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---
Dennis Taylor