Re: Subversion 1.9.0-dev FSFS performance tests
From: Julian Foad <julianfoad_at_btopenworld.com>
Date: Mon, 7 Jul 2014 17:44:28 +0100
I should probably let Stefan answer this, but...
C. Michael Pilato wrote:
Ivan, it sounds like you've missed the important part of the design. It's designed to do LESS work in total, not more, because the cost of using the index is outweighed by the savings that it enables. As I understand it, a large saving is gained by re-ordering the data on disk during packing; that's why packing is essentially a requirement.
>>> I'm coming into this kinda late and after two weeks of vacation, so
C-Mike, my understanding is that F7 comprehensively beats F6 speed, by large factors around x1.5 and more, in the kind of scenarios it's designed for. Caching is an assumed part of the design. I don't know how much it needs for what scenarios, or what you mean by 'non-trivial' or 'ginormous', but probably not as much as you might be led to think. I suggest you first look at Stefan's recent-ish test results  and other recent threads.
The only concerns about speed are about scenarios where it doesn't match F6 speed. While many scenarios are faster, some are slower, especially with the currently-default small cache size. Ivan reported some such scenarios .
My general observation is that wider testing is needed to draw firm conclusions.
 "Re: Current FSFS performance [RAW]" <http://svn.haxx.se/dev/archive-2014-07/0004.shtml>
 "Subversion 1.9.0-dev FSFS performance tests" <http://svn.haxx.se/dev/archive-2014-06/0065.shtml>
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