Comments on: Proof of the Farthest-in-Future Optimal Caching Algorithm https://blog.henrypoon.com/blog/2014/02/02/proof-of-the-farthest-in-future-optimal-caching-algorithm/ Sat, 29 Aug 2020 08:14:58 +0000 hourly 1 By: henrypoon https://blog.henrypoon.com/blog/2014/02/02/proof-of-the-farthest-in-future-optimal-caching-algorithm/#comment-9045 Sat, 29 Aug 2020 08:14:58 +0000 http://henrypoon.mooo.com/blog/proof-of-the-farthest-in-future-optimal-caching-algorithm#comment-9045 In reply to Sarika Tammali.

The cache miss requirement here is minimising the amount of times where a thing is being requested that isn’t in the cache since this requires evicting an item and inserting a new item.

]]> By: Sarika Tammali https://blog.henrypoon.com/blog/2014/02/02/proof-of-the-farthest-in-future-optimal-caching-algorithm/#comment-9044 Sat, 29 Aug 2020 04:05:34 +0000 http://henrypoon.mooo.com/blog/proof-of-the-farthest-in-future-optimal-caching-algorithm#comment-9044 Thank you for the blog. It is almost clear. But I am not understanding the phrase thus fulfilling cache miss requirement. What is a cache miss requirement? Also in case 3C when S’ and SFF are getting items that are not needed and evicting some items. How this is leading to cache miss? How to convert us reduced to reduced in Case 3C? Also when we do this there will not be cache miss right? Then how are you saying S’ and SFF will have a cache miss?Could you please reply if you can?

]]> By: Applications of Greedy technique - Programmer Notes https://blog.henrypoon.com/blog/2014/02/02/proof-of-the-farthest-in-future-optimal-caching-algorithm/#comment-9033 Sat, 16 Feb 2019 17:20:22 +0000 http://henrypoon.mooo.com/blog/proof-of-the-farthest-in-future-optimal-caching-algorithm#comment-9033 […] indeed the only optimal strategy of the five presented. The proof is rather long and can be found here or in the book by Jon Kleinberg and Eva Tardos (see sources in remarks down […]

]]> By: algorithm – Applications of Greedy technique – Offline Caching - CodeDay https://blog.henrypoon.com/blog/2014/02/02/proof-of-the-farthest-in-future-optimal-caching-algorithm/#comment-9024 Fri, 19 Oct 2018 03:06:33 +0000 http://henrypoon.mooo.com/blog/proof-of-the-farthest-in-future-optimal-caching-algorithm#comment-9024 […] indeed the only optimal strategy of the five presented. The proof is rather long and can be found here or in the book by Jon Kleinberg and Eva Tardos (see sources in remarks down […]

]]> By: henrypoon https://blog.henrypoon.com/blog/2014/02/02/proof-of-the-farthest-in-future-optimal-caching-algorithm/#comment-8851 Mon, 15 Aug 2016 06:10:09 +0000 http://henrypoon.mooo.com/blog/proof-of-the-farthest-in-future-optimal-caching-algorithm#comment-8851 In reply to Shuqin Lee.

Hi Shuqin,

It’s been a while since I’ve looked at this subject, but I’ll try to answer your questions:

1. There is a good explanation here: https://www.cs.princeton.edu/courses/archive/spring13/cos423/lectures/04GreedyAlgorithmsI.pdf (page 38)

2. This is just a mathy way of expressing that S and S’ after j and j+1 requests should not have incurred more cache misses compared to SFF and that the cache misses incurred by S’ is not more than S.

]]> By: Shuqin Lee https://blog.henrypoon.com/blog/2014/02/02/proof-of-the-farthest-in-future-optimal-caching-algorithm/#comment-8848 Thu, 11 Aug 2016 13:11:56 +0000 http://henrypoon.mooo.com/blog/proof-of-the-farthest-in-future-optimal-caching-algorithm#comment-8848 Hi, I’ve been reading your article for hours and there still are some points that I haven’t make clear:

1. Why is it possible to transform an unreduced schedule into a reduced schedule? [quoted from section Case 3c]

2. In the section Proof, you said that we want S = S’ = SFF after a request is made and that the number of cache misses have not increased. That the part I cannot understand the most. First, what’s the difference between SFF and S’? Why bother have S’? Secondly, why we want SFF = S?

This can be stupid questions, but there must be some important points that I’s missing here. Thank you very muif you give some hints~

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