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Performance question

From: Bill Mann <bill.mann_at_worldtalk.com>
Date: Thu, 17 Jun 1999 11:21:17 -0700
Message-ID: <37693C9D.33F982EE@worldtalk.com>


Can anyone comment on the performance of the following select statement when most of the rows in the table will contain NULL values for the
"hobbies" varchar2(1024) column.

The "hobbies" will be a string with the following format
"football:hockey:cricket..."

I already know that this type of search is slow since Oracle needs to scan the string completely. Since most rows are NULL, will Oracle still walk thru each row ? Is it worth indexing the someinfo column, to stop Oracle from checking rows containing Nulls ?

THanks,
Bill

SELECT name from employee

    where
    hobbies like '%football%' Received on Thu Jun 17 1999 - 13:21:17 CDT

Original text of this message

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