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Re: SHOULD use POST for expensive queries?

From: Kendall Clark <kendall@monkeyfist.com>
Date: Wed, 18 Jan 2006 10:38:03 -0500
Message-Id: <2BB28922-605E-4A60-BCD0-96BB1C7F268C@monkeyfist.com>
Cc: dawg mailing list <public-rdf-dawg@w3.org>
To: andy.seaborne@hp.com


On Jan 18, 2006, at 10:26 AM, Seaborne, Andy wrote:

>>  Even very sophisticated query analysis can't tell  you which RDF  
>> datasets are expensive to assemble.
>
> Very true.  It's not just the query that determines whether it will  
> be expensive - it's the dataset as well (and the sever load).

Actually, now that I think about it, that's not *entirely* true. Real  
(as opposed to toy) database cost models include table size, and even  
for arbitrary 3rd party graphs, with clever caching and use of HTTP,  
a SPARQL query analyzer could make some good guesses (so, imagine the  
ideal case: all the graphs are cached locally and known to be fresh),  
so it's not as bad as I made it seem.

But in the common or pathological cases (where all graphs are  
unknown, uncached, and have to be retrieved from arbitrary origin  
servers), well... -shudder-.

Cheers,
Kendall
--
You're part of the human race
All of the stars and the outer space
Part of the system again
Received on Wednesday, 18 January 2006 15:39:39 GMT

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