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Re: SQL Tunning using Indexes

From: Jonathan Lewis <jonathan_at_jlcomp.demon.co.uk>
Date: Thu, 23 Nov 2000 16:49:17 -0000
Message-ID: <974994549.25269.0.nnrp-09.9e984b29@news.demon.co.uk>

Can you take a closer look at the multiple extents that are produced when doing parallel insert/update.

Since (as you point out) you are using partitioned tables, your insert can only execute as a parallel insert by splitting the data across multiple partitions - so your 'multiple extents' could actually be 'one extent per partition loaded'.

--
Jonathan Lewis
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Book bound date: 8th Dec 2000
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Lynux wrote in message <8vjaec$1fl3_at_imsp212.netvigator.com>...

>Are there any ways or initial parameter to make parallel query on index
>scan and retain single query on insert, update?
>
>From previous experience, we can parallel query using index by using
>HARDCODED hints or change the degree of the index (it must be partitioned)
>However, if an insert or update is performed on the table and make the
>index grow beyond its available space. Instantly, several extends (same as
>the index's degree) would also be producted instead of 1 extends at a
>time. If we use degree 1 for the index, then index scan would possibly
>need about 20 - 200 times lower than table scan.
>
>Do anyone got the same experience and/or share your opinions?
>
>Thanks in Advance!
Received on Thu Nov 23 2000 - 10:49:17 CST

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