From: Yuri T. <ti...@gm...> - 2008-10-14 08:45:03
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2008/10/14 Kern Sibbald <ke...@si...>: > On Tuesday 14 October 2008 10:06:22 Yuri Timofeev wrote: >> 2008/10/14 Kern Sibbald <ke...@si...>: >> > On Tuesday 14 October 2008 09:39:27 John Huttley wrote: >> >> So the modified version is actually a bit faster? >> > >> > That is what I understood too, but I wanted to get a confirmation. >> > >> > If it is indeed the case that the new case runs faster, it is indeed odd, >> > and I would say the tester has fallen into a very trap that is very >> > common in performance analysis. >> >> Of course, this is only the first test! >> I think that will soon be able to hold a series of tests. >> I just limiting the number of entries from 10M to 5M (very long wait) > > Yes, clearly running something 10 times is not very practical if it takes 35 > hours each time, so the test size must be reduced, and you can reduce the > number of runs from 10 to say 5. > > However, what was not at all evident from your first post is that there are > apparently subtle differences in schemas that I did not see and differences > in the size of the data you were inserting -- and those could possibly > explain a large (or even all) the difference in timings. > In an alternative scheme appear new fields : size, ctime, mtime. I therefore reduced length the value that is inserted into the field LStat. For the old scheme, I used : char *lstat = "MI s9MB IG0 B H2 H0 A 9t BAA I BIVsDs BIR93m BIVqaC A A E"; and for the new scheme: char *lstat = "MI s9MB IG0 B H2 H0 A 9t BAA I"; But it is not entirely correct. In an alternative scheme2 appear new fields : size, ctime, mtime, _atime_. The new version of the tests, I did as correctly: char *lstat = "MI s9MB IG0 B H2 H0 A 9t BAA I BIVsDs BIR93m BIVqaC A A E"; /* for traditional scheme */ char *lstat = "MI s9MB IG0 B H2 H0 A BAA I BIVsDs BIR93m BIVqaC"; /* for new scheme */ Therefore, in alternative scheme the length of lstat reduced. That is right? -- with best regards |