Udrea2007grin question 1 by lebo

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CSCI 6966 Advanced Semantic Web (Fall 2008)


A Question from Tim Lebo about udrea2007grin:

It would seem that the method used to determine cluster centers would drastically influence query performance. The selected clustering algorithm (e.g., PAM) and the inter-cluster metric (e.g., single, complete, or average link) would both be factors of performance. The authors do not commit to an inter-cluster distance metric d_c and devote one sentence discussing the results of the comparison: They all "performed" the same within 5%.

  1. Why do you suppose GRIN's index creation times, index sizes, and query times were invariant to the inter-cluster metric used?

Medha GRIN Presentation

  • Answer: This is a good question. The answer is two fold. In GRIN index building and query execution, authors have made use of some graph mining, clustering algorithms, which I am not very familiar with. Since the features and performance characteristics of these two algorithms are not know and also there isn't a lot of literature present on usage of these algorithms for RDF graphs, it's difficult to comment on whether or not performance characteristics of these algorithms affect efficiency of GRIN index.
Facts about Udrea2007grin question 1 by leboRDF feed
AQuestion  +
AboutUdrea2007grin  +
AuthorTim Lebo  +
Question answerThis is a good question. The answer is two This is a good question. The answer is two fold. In GRIN index building and query execution, authors have made use of some graph mining, clustering algorithms, which I am not very familiar with. Since the features and performance characteristics of these two algorithms are not know and also there isn't a lot of literature present on usage of these algorithms for RDF graphs, it's difficult to comment on whether or not performance characteristics of these algorithms affect efficiency of GRIN index. lgorithms affect efficiency of GRIN index.
Question askedIt would seem that the method used to dete It would seem that the method used to determine cluster centers would drastically influence query performance. The selected clustering algorithm (e.g., PAM) and the inter-cluster metric (e.g., single, complete, or average link) would both be factors of performance. The authors do not commit to an inter-cluster distance metric d_c and devote one sentence discussing the results of the comparison: They all "performed" the same within 5%.
  1. Why do you suppose GRIN's index creation times, index sizes, and query times were invariant to the inter-cluster metric used? nvariant to the inter-cluster metric used?
Question asked byTim Lebo  +
Question for the PresentationMedha GRIN Presentation  +
TextIt would seem that the method used to dete It would seem that the method used to determine cluster centers would drastically influence query performance. The selected clustering algorithm (e.g., PAM) and the inter-cluster metric (e.g., single, complete, or average link) would both be factors of performance. The authors do not commit to an inter-cluster distance metric d_c and devote one sentence discussing the results of the comparison: They all "performed" the same within 5%.
  • Why do you suppose GRIN's index creation times, index sizes, and query times were invariant to the inter-cluster metric used? nvariant to the inter-cluster metric used?
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