Re: Limit on number of columns in an index

From: Ram Raman <veeeraman_at_gmail.com>
Date: Wed, 19 Mar 2008 15:06:17 -0500
Message-ID: <effc058d0803191306r6b111e05v95fc373bcaf242b4@mail.gmail.com>


The table has 60 columns. The problem is that this is a temporary table which gets used only when the process is run and gets truncated afterwards. While running, currenlty it gets populated with 1.4 million rows. The rows are inserted and then updated based on several criteria. Towards the end of the process, the values from this table are inserted to another permanent table. The process is taking more than 2x longer now (2+ hrs now) than before because of increased volumes of data.

The insertion was slow, I tuned it. Many update statements are issued against the temp table. I am trying to make things faster. I tried creating few indexes ont he temp table(!). Hope they dont slow down the insertions. I did not try parallelizing the queries.

Env: Pplsoft, 10g

On 3/19/08, Bobak, Mark <Mark.Bobak_at_proquest.com> wrote:
>
> Well, as with all things, there's no hard rule…but 30 does seem like a
> lot…..
>
>
>
> How many total columns in the base table? Have you considered making the
> table an IOT instead?
>
>
>
> -Mark
>
>
>
> *--
> Mark J. Bobak*
> *Senior Database Administrator, System & Product Technologies*
> ProQuest
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> Ann Arbor MI 48106-1346
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>
>
> *From:* oracle-l-bounce_at_freelists.org [mailto:
> oracle-l-bounce_at_freelists.org] *On Behalf Of *Ram Raman
> *Sent:* Wednesday, March 19, 2008 1:59 PM
> *To:* oracle-l
> *Subject:* Limit on number of columns in an index
>
>
>
> Listers,
>
>
>
> Is there any limit on the number of columns a BTree index can have, before
> it is considered a bad design. I see a need to build an index with almost 30
> columns.
>
>
>
> Thanks
>

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Received on Wed Mar 19 2008 - 15:06:17 CDT

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