On Friday 24 October 2008, Kari Laine wrote: > Hi, > > referring to discussion few days back I have now tested md5sum with 540388 > files and got NO collisions - I think. Method I used was to calculate md5sum > and sha512sum for all those files. > then I asked from database distinct total values for both fields and they > come up with the same number. In my thinking if there would have been > collisions with md5sum then numbers should have differed. > Problem is that if md5sum and sha512sum would have collisions with the same > file - but I think that's quite unlikely - is it?
I can't imagine that will happen, you are right in my opinion. > > I make my backup program to take a file identified by sha512sum and size. I > am not going to run compare for all the files because that would take a > month with my machine. Calculating the checksums took about a week because > there were total 1240333 files. So lot of duplicates which is exactly why I > want to make the program copy files only once. > > Best Regards > Kari Laine Nice to hear the result. So the theory story is now proven by your test. Did you see a big difference between the used time for md5 and sha methods? Anyway happy cleaning up your archive and backing up the remaining part. Best regards Ron_1st ------------------------------------------------------------------------- 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=/ _______________________________________________ Gambas-user mailing list Gambas-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/gambas-user
