2008/10/14 Kern Sibbald <[EMAIL PROTECTED]>: > On Tuesday 14 October 2008 10:42:22 Yuri Timofeev wrote: >> 2008/10/14 Kern Sibbald <[EMAIL PROTECTED]>: >> > On Tuesday 14 October 2008 10:06:22 Yuri Timofeev wrote: >> >> 2008/10/14 Kern Sibbald <[EMAIL PROTECTED]>: >> >> > 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? > > I would not say it is a question of being right or not. It is a possibility, > but it would be a big effort to eliminate those fields -- first there is the > programming problem of finding every place they are accessed and ensuring the > new fields are used, but even more important, there is the problem of > converting existing databases from the old scheme to the new one. > > >
Yes, I agree. Perhaps these studies will never be translated into bacula source code. However, it is interesting. -- with best regards ------------------------------------------------------------------------- This SF.Net email is sponsored by the Moblin Your Move Developer's challenge Build the coolest Linux based applications with Moblin SDK & win great prizes Grand prize is a trip for two to an Open Source event anywhere in the world http://moblin-contest.org/redirect.php?banner_id=100&url=/ _______________________________________________ Bacula-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/bacula-devel
