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DATE 2015-04-01

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MESSAGE
DATE 2015-04-14
FROM Ruben Safir
SUBJECT Subject: [LIU Comp Sci] hashing slots sizes
From owner-learn-outgoing-at-mrbrklyn.com Tue Apr 14 10:36:11 2015
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we have in the notes that chosing

m=2**P is a poor choice since k % 2**p is the p lowest-order bits of m.

I'm running some numbers to see if I understand the nature of this problem

is m is 2**4 (16) and then k is 31 then the slot from the hash is 15
so that is good. And 30 is 14. It seems like as good as any other
distribution which can be constructed.

You then give the example of a 000 keys all ending up on the zero slot
and conclude that it is a good idea to have a hash key that depends all
all the bits.

First, I'm not certain that is possible regardless how m is represented
BUT, the issue here seems to be the number of keys slots (or the size of
m). the significance of the bits don't matter, but replication is a
big problem. Regardless of the m chosen, the slots will replicate in a
cycle ever m times in a cycle. Are we trying to create cryptography or
a hash? Also do we know that the data will have lots of 000 numbers?
If so then we would want to adjust m

  1. 2015-04-01 Ruben <mrbrklyn-at-panix.com> Subject: [LIU Comp Sci] external paths
  2. 2015-04-01 Ruben Safir <mrbrklyn-at-panix.com> Subject: [LIU Comp Sci] omp pthread madness
  3. 2015-04-02 Ruben Safir <mrbrklyn-at-panix.com> Subject: [LIU Comp Sci] Fwd: Fw: Perl Developer / Linux SysAdmin Opportunities in South Florida
  4. 2015-04-02 Ruben Safir <mrbrklyn-at-panix.com> Subject: [LIU Comp Sci] Fwd: omp pthread madness
  5. 2015-04-02 Ruben Safir <mrbrklyn-at-panix.com> Subject: [LIU Comp Sci] Fwd: omp pthread madness
  6. 2015-04-02 Ruben Safir <mrbrklyn-at-panix.com> Subject: [LIU Comp Sci] Fwd: [New discussion] which technologies/skills are good to have
  7. 2015-04-02 Ruben Safir <mrbrklyn-at-panix.com> Subject: [LIU Comp Sci] Re: omp pthread madness
  8. 2015-04-05 Ruben Safir <mrbrklyn-at-panix.com> Subject: [LIU Comp Sci] Re: Depths and heights
  9. 2015-04-09 Ruben Safir <mrbrklyn-at-panix.com> Subject: [LIU Comp Sci] Re: Kernel thread scheduling
  10. 2015-04-09 Ruben Safir <mrbrklyn-at-panix.com> Subject: [LIU Comp Sci] Re: Kernel thread scheduling
  11. 2015-04-13 Ruben Safir <mrbrklyn-at-panix.com> Subject: [LIU Comp Sci] BASh Shell Scripting
  12. 2015-04-13 Ruben Safir <mrbrklyn-at-panix.com> Subject: [LIU Comp Sci] Chapter 5 Monitor
  13. 2015-04-13 Ruben Safir <mrbrklyn-at-panix.com> Subject: [LIU Comp Sci] Fwd: [Perlweekly] #194 - The CPAN PR Challenge Now Has a Mini-Me!
  14. 2015-04-13 Ruben Safir <mrbrklyn-at-panix.com> Subject: [LIU Comp Sci] Kernel Hacking Resources
  15. 2015-04-14 Ruben Safir <mrbrklyn-at-panix.com> Subject: [LIU Comp Sci] Fwd: Invitation: Vintage Computer Festival
  16. 2015-04-14 Ruben Safir <mrbrklyn-at-panix.com> Subject: [LIU Comp Sci] hashing slots sizes
  17. 2015-04-15 Ruben <mrbrklyn-at-panix.com> Re: [LIU Comp Sci] BASh Shell Scripting
  18. 2015-04-15 Maneesh Kongara <maneeshkongara-at-gmail.com> Re: [LIU Comp Sci] BASh Shell Scripting
  19. 2015-04-15 Ruben Safir <mrbrklyn-at-panix.com> Subject: [LIU Comp Sci] Fwd: Monday: Join 121 HackerNestologists at "HackerNest NYC April
  20. 2015-04-15 Ruben Safir <mrbrklyn-at-panix.com> Subject: [LIU Comp Sci] Fwd: You're confirmed for: NYLUG Open hacker hours
  21. 2015-04-15 Ruben Safir <mrbrklyn-at-panix.com> Subject: [LIU Comp Sci] Hash Tables Examples
  22. 2015-04-15 Ruben Safir <mrbrklyn-at-panix.com> Subject: [LIU Comp Sci] Re: hashing quadradic probes
  23. 2015-04-15 Ruben Safir <mrbrklyn-at-panix.com> Subject: [LIU Comp Sci] [ruben-at-mrbrklyn.com: Re: Heap Management Problem]
  24. 2015-04-16 Ruben Safir <mrbrklyn-at-panix.com> Subject: [LIU Comp Sci] Fwd: Re: virtualbox
  25. 2015-04-16 Ruben Safir <mrbrklyn-at-panix.com> Subject: [LIU Comp Sci] linsched
  26. 2015-04-16 Ruben Safir <mrbrklyn-at-panix.com> Subject: [LIU Comp Sci] scheduler project thus far
  27. 2015-04-17 Ruben Safir <mrbrklyn-at-panix.com> Subject: [LIU Comp Sci] Come Sunday Morning
  28. 2015-04-17 Ruben Safir <mrbrklyn-at-panix.com> Subject: [LIU Comp Sci] Kernel Scheduling Project
  29. 2015-04-17 Ruben <ruben.safir-at-my.liu.edu> Subject: [LIU Comp Sci] more advanced coding musings ...
  30. 2015-04-19 Tony Genao <tony.genao-at-my.liu.edu> Re: [LIU Comp Sci] Fwd: [NYLXS - HANGOUT] Summers Here
  31. 2015-04-19 Ruben Safir <mrbrklyn-at-panix.com> Re: [LIU Comp Sci] Fwd: [NYLXS - HANGOUT] Summers Here
  32. 2015-04-19 Tony Genao <tony.genao-at-my.liu.edu> Re: [LIU Comp Sci] Fwd: [NYLXS - HANGOUT] Summers Here
  33. 2015-04-19 Ruben <mrbrklyn-at-panix.com> Re: [LIU Comp Sci] Fwd: [NYLXS - HANGOUT] Summers Here
  34. 2015-04-19 Tony Genao <tony.genao-at-my.liu.edu> Re: [LIU Comp Sci] Fwd: [NYLXS - HANGOUT] Summers Here
  35. 2015-04-19 Ruben Safir <mrbrklyn-at-panix.com> Subject: [LIU Comp Sci] Fwd: [NYLXS - HANGOUT] Summers Here
  36. 2015-04-19 Ruben Safir <mrbrklyn-at-panix.com> Subject: [LIU Comp Sci] Re: The more I learn the less I know
  37. 2015-04-22 Ruben Safir <mrbrklyn-at-panix.com> Subject: [LIU Comp Sci] Fwd: Re: wait queues semiphores kernel implementations
  38. 2015-04-22 Ruben Safir <mrbrklyn-at-panix.com> Subject: [LIU Comp Sci] linux locks and mutex
  39. 2015-04-23 Ruben Safir <mrbrklyn-at-panix.com> Subject: [LIU Comp Sci] Fwd: Re: Kernel Scheduler and wiat queues
  40. 2015-04-25 Ruben Safir <mrbrklyn-at-panix.com> Subject: [LIU Comp Sci] Fwd: Kernel Scheduling and wait queues
  41. 2015-04-27 Ruben Safir <mrbrklyn-at-panix.com> Subject: [LIU Comp Sci] Fwd: OS Cpt 9 27 question
  42. 2015-04-27 Ruben Safir <mrbrklyn-at-panix.com> Subject: [LIU Comp Sci] Fwd: Tomorrow: You and 30 other Flatirons are going to "Flatiron
  43. 2015-04-28 Ruben Safir <mrbrklyn-at-panix.com> Subject: [LIU Comp Sci] Re: DMCA exemption commenting process broken beyond repair
  44. 2015-04-29 Ruben Safir <mrbrklyn-at-panix.com> Subject: [LIU Comp Sci] Do you have notes for this question
  45. 2015-04-29 Ruben Safir <mrbrklyn-at-panix.com> Subject: [LIU Comp Sci] Professional Troll job available
  46. 2015-04-29 Ruben <mrbrklyn-at-panix.com> Subject: [LIU Comp Sci] Re: DMCA exemption commenting process broken beyond repair

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