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Re: context intermedia newbie question

From: John Russell <netnews4_at_johnrussell.mailshell.com>
Date: Sat, 02 Nov 2002 05:41:56 GMT
Message-ID: <6tm6su4ab1qi8tcrt7rkboqshusatmh20i@4ax.com>


On 23 Oct 2002 12:27:29 -0700, ewong_at_mail.com (Ed Wong) wrote:
>2. What about performace on search such a big CLOB using context
>intermedia? Does it return result immediately for simple search such
>as "CONTAINS(Resume,'engineering')>0;"

The way Context / interMedia / Oracle Text works makes this very fast. Behind the scenes, it builds internal tables and indexes so that for every different word, it can instantly tell which rows contain it.

>3. Can I use context to create an index on varchar2 so that an index
>will be use for wildcard search '%text%'?

I don't think so, if I understand what you mean. But I don't think it matters much. When you say CONTAINS(Resume,'%text%'), there is a full table scan, but from what I understand it scans the table that has all the unique words. So even if you have a 30GB CLOB column, it might only have 50,000 different words and so the FTS would go through 50,000 rows, not your 30GB of data. I use wildcards on either side of terms inside CONTAINS, but performance is still OK.

John Received on Fri Nov 01 2002 - 23:41:56 CST

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