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Re: CBO and index usage

From: Jill <jc_va_at_hotmail.com>
Date: Sun, 22 Aug 1999 06:31:18 -0700
Message-ID: <7pojib$bfe$1@bgtnsc02.worldnet.att.net>


I think if you say

"cust# > 0 and sales_order like..."

then Oracle will read the index. If you put an explicit hint on the query to use the index, it may basically do the same thing. But as Mr. Bakker says, this isn't necessarily better.

usmrall wrote in message <7pn45b$4ho$1_at_nnrp1.deja.com>...
>Hello,
>I have an index comprising of the following columns
>cust#
>sales order
>line item
>order date
>and the table has been analyzed . The adhoc query application
>can issue a query on any combination of these columns (and in any order)
>when i issue a like query i.e 'where sales order like '<some value>%''
>and run an explain plan on it, the results indicate a full table scan.
>why doesn't oracle use the index ? it already has an indexed set of
>values to choose from.
>Also, does this mean that i have to create an index for each combination
>of predicates ?
>please help
>
>
>Sent via Deja.com http://www.deja.com/
>Share what you know. Learn what you don't.
Received on Sun Aug 22 1999 - 08:31:18 CDT

Original text of this message

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