- From: Kendall Clark <kendall@monkeyfist.com>
- Date: Wed, 18 Jan 2006 10:38:03 -0500
- To: andy.seaborne@hp.com
- Cc: dawg mailing list <public-rdf-dawg@w3.org>
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 UTC