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RE: JW10: QSD usage

From: Niket Patwardhan <niket@verity.com>
Date: Tue, 10 Aug 1999 10:18:28 -0700
Message-Id: <199908101716.kaa10321@verity.com>
To: Jim Davis <jrd3@alum.mit.edu>
Cc: www-webdav-dasl@w3.org
Two different search engines are going to return different documents
(that's reality). Even the same search engine will return different
documents if set up to interpret the document differently. (For example, if
they have different thesaurii) But it would be nice to ask "Does this field
exist, and if so, pay attention to this part of the whole query". So it
could be acceptable.

But I think what you are getting at is that we need to identify the
conditions and a subset of the full query language which an expert knows
would get exactly the same answers from all servers.

Niket Patwardhan

At 05:09 PM 8/9/99 -0700, you wrote:
>At 05:03 PM 8/9/99 -0700, Niket Patwardhan wrote:
>>I think the key is what you mean by "succeed". The SQL model is to flag
>>problems (such as column names that don't exist) as an error, causing the
>>whole query to fail. The usual text retrieval philosophy is to avoid
>>returning errors, by treating that portion of the query as either true,
>>false or don't care. Given that type of philosophy, things would always
>>succeed, but would return more or less documents depending on the server.
>
>that's where the three-valued logic (as explained by Alan) comes in.
>
>the query won't fail (by fail I mean return a 4xx or 5xx) for missing
>columns.  But if the column isnt there, the query won't MATCH either.
>
>Is this acceptable?
> 
Received on Tuesday, 10 August 1999 13:18:54 GMT

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