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Re: tablescans vs indexed scan

From: Steve McDaniels <steve.mcdaniels_at_sierra.com>
Date: Thu, 20 Jan 2000 13:22:31 -0800
Message-ID: <867uj2$pgv$1@plo.sierra.com>

  1. Are all needed fields indexed?
  2. Are users performing queries that cannot use the indexes? (where substr(an_indexed_field) = some_value)

SC <s_c_99_at_hotmail.com> wrote in message news:38873BBC.5E6225E1_at_hotmail.com...
> Hello,
>
> Our database is going very slow (Oracle 7.3.3.6, Open VMS-7.1)
> and we discovered that many queries are performing tablescans
> rather than indexed scans. This is increasing
> Input/Output drastically and hence the database is very slow.
>
> Could anyone please advise me how can I make the query to
> use indexes? I am sure that the indexes exist as we have
> always been using them. So why the performance is going
> down NOW ? Will rebuilding indexes be any help?
> Also how can i detect which indexes are used and
> which ones arent?
>
> Please Help. (please send me an email at s_c_99_at_hotmail.com
> as well)
>
> Thanks.
>
> SC.
Received on Thu Jan 20 2000 - 15:22:31 CST

Original text of this message

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