Skip navigation
Currently Being Moderated

CreateUUID

Feb 23, 2012 8:41 AM

 
Replies 1 2 Previous Next
  • Currently Being Moderated
    Feb 23, 2012 8:41 AM   in reply to Community Help

    I'm confused about one aspect of UUIDs: In CF9 standard, if I check the "Use UUID for CKToken", it generates a token that has the 8-4-4-16 character group, but in a addition, it is prefixed by another string, so that the CFTOKEN returned looks something like this: 360353802d5624bb-AD53DEC4-E04D-3E5F-F75EA5F06E6AD3A5.  Because of that extra prefix, if I try to write the CFToken to a database table, and use  it throws the following error:

     

    ERROR INFORMATION:

    The cause of this output exception was that: coldfusion.tagext.sql.QueryParamTag$InvalidDataException: Invalid data value 360353802d5624bb-AD53DEC4-E04D-3E5F-F75EA5F06E6AD3A5 exceeds maxlength setting 50.

     

    So, my questions are: when using UUID for CFToken, what should the maxlength be set to to ensure successful writes, where is the prefix before the  8-4-4-16 character group coming from, and what does that prefix represent?

     

    Thanks,

    Michael

     
    |
    Mark as:
  • Currently Being Moderated
    Feb 23, 2012 10:08 AM   in reply to mpconsumer

    ColdFusion prepends the UUID with 16 random hexadecimal characters to make the CFToken even more unique. See the section "Ensuring CFToken uniqueness and security" in the livedocs on managing the client state.

     
    |
    Mark as:
  • Currently Being Moderated
    Feb 23, 2012 10:13 AM   in reply to BKBK

    ColdFusion prepends the UUID with 16 random hexadecimal characters to make the CFToken even more unique. See the section "Ensuring CFToken uniqueness and security" in the livedocs on managing the client state.

     

    Because, like, a UUID is not unique enough already.

     

    :-|

     

    I do wonder about them (Adobe) sometimes.  [Shrug].  Maybe there's some good reason to do this that I'm not seeing.

     

    --

    Adam

     
    |
    Mark as:
  • Currently Being Moderated
    Feb 23, 2012 10:33 AM   in reply to Adam Cameron.

    The random string is not meant to make the token more unique, it is meant to make it random.  UUIDs are plenty unique, but A CF UUID is not random. For a token to be a quality session token it must be random, hence the extra string.

     
    |
    Mark as:
  • Currently Being Moderated
    Feb 23, 2012 11:36 AM   in reply to 12Robots

    Yeah... OK. But only the first four bytes of a CF UUID is not random.  The rest is.  So I really don't see the benefit still.  I suppose "more numbers" means "more randomness", but they've already got 96-bits worth of random there.  That's quite a lot.

     

    --

    Adam

     
    |
    Mark as:
  • Currently Being Moderated
    Feb 23, 2012 12:55 PM   in reply to Adam Cameron.

    Is that documented anywhere?  Because I do not think that is true. I don't think that CF UUIDs are anywhere near that random (if random at all). Perhaps it has changed over the years, but in the past CF would produce UUIDs like this:

     

    1330544F-C09F-F023-3B5732BB3AB1E6FC

    1330546E-C09F-F023-3B427B03747AD651

    1330547E-C09F-F023-3B32F655A3898333

    1330548D-C09F-F023-3B272F4E96E41BED

    1330549D-C09F-F023-3B342477C11A9E36

     

    Now they appear to be better

     

    B7D7C0B8-B308-5369-EFC0BE4E04761AE2

    B7D7C0BB-E912-DFB2-214CA7DB792CE7E8

    B7D7C0BC-DA8E-AC19-E975FC9328DF931F

    B7D7C0BD-DD8B-D5C5-4BE0F86B97BDE54F

    B7D7C0BE-F2D2-E4B8-5E5D4DEDD32E54CF

     

    But for whatever reason clearly it was not deemed sufficient. Perhaps it was pressure from those that wanted something more for PCI compliance.  I certainly don't think it was a bad move or anything. The more randomness the better.

     

    jason


     
    |
    Mark as:
  • Currently Being Moderated
    Feb 23, 2012 12:59 PM   in reply to 12Robots

     

    Is that documented anywhere?

    Documented?  Not that I'm aware of.  But I was looking at the source code of the createUuid() function (in CF9).

     

    --

    Adam

     
    |
    Mark as:
  • Currently Being Moderated
    Feb 23, 2012 1:07 PM   in reply to Adam Cameron.

    Good enough for me.

     

    Jason

     
    |
    Mark as:
  • Currently Being Moderated
    Feb 23, 2012 10:17 PM   in reply to 12Robots

    12Robots wrote:

     

    The random string is not meant to make the token more unique, it is meant to make it random. 

    Actually, more unique means random!

     
    |
    Mark as:
  • Currently Being Moderated
    Feb 24, 2012 7:36 AM   in reply to BKBK

    No, it doesn't. I could increment numbers 1,2,3,4,5,6,7 and guarantee uniquiness. But they certainly are not random. Uniqueness and Random are not the same thing.

     

    Jason

     
    |
    Mark as:
  • Currently Being Moderated
    Feb 25, 2012 2:19 PM   in reply to 12Robots

    12Robots wrote:

     

    No, it doesn't. I could increment numbers 1,2,3,4,5,6,7 and guarantee uniquiness. But they certainly are not random. Uniqueness and Random are not the same thing.

    In your example, uniqueness means distinctness. The list you give is deterministic.

     

    In the above context (of CFToken) uniqueness and randomness are synonymous. They are both measures of the effectiveness of the random generator. In this sense, uniqueness means that, if you pick one CFToken from an extremely large list of CFTokens generated by ColdFusion, the probability of there being another one identical to it is negligible. Randomness means, if you pick any arbitrary number of consecutive CFTokens in the list,  you will be unable to find an algorithm to use them to predict the next one.

     
    |
    Mark as:
  • Currently Being Moderated
    Feb 25, 2012 2:24 PM   in reply to 12Robots

    12Robots wrote:

     

    The random string is not meant to make the token more unique, it is meant to make it random. 

    Adobe themselves named that section of the livedocs: "Ensuring CFToken uniqueness and security".

     
    |
    Mark as:
  • Dave Watts
    747 posts
    Mar 11, 2003
    Currently Being Moderated
    Feb 26, 2012 10:22 AM   in reply to BKBK

    In the above context (of CFToken) uniqueness and randomness are synonymous. They are both measures of the effectiveness of the random generator. In this sense, uniqueness means that, if you pick one CFToken from an extremely large list of CFTokens generated by ColdFusion, the probability of there being another one identical to it is negligible. Randomness means, if you pick any arbitrary number of consecutive CFTokens in the list,  you will be unable to find an algorithm to use them to predict the next one.

     

    While they are both measures of the effectiveness of the random number generator, they do not mean the same thing, regardless of within what context they're used.

     

    Dave Watts, CTO, Fig Leaf Software

     
    |
    Mark as:
  • Currently Being Moderated
    Feb 26, 2012 12:13 PM   in reply to Dave Watts

    BKBK wrote:

     

    In the above context (of CFToken) uniqueness and randomness are synonymous. They are both measures of the effectiveness of the random generator. In this sense, uniqueness means that, if you pick one CFToken from an extremely large list of CFTokens generated by ColdFusion, the probability of there being another one identical to it is negligible. Randomness means, if you pick any arbitrary number of consecutive CFTokens in the list,  you will be unable to find an algorithm to use them to predict the next one.

     

    Dave Watts wrote:

     

    While they are both measures of the effectiveness of the random number generator, they do not mean the same thing, regardless of within what context they're used.

    A statement with just the bare bones and no beef gives us little to chew on. As an aside, I do believe that the clause "regardless of within what context" exists out of the realms of language and logic. For context is one of the fundaments of language and logic. I'll leave it here, lest the argument stray even further away from the CFToken.

     
    |
    Mark as:
  • Dave Watts
    747 posts
    Mar 11, 2003
    Currently Being Moderated
    Feb 26, 2012 12:23 PM   in reply to BKBK

    I will simplify it for you. There is no context in which uniqueness and randomness mean the same thing. Period. There is nothing here for you to "chew on" - it's a very simple thing.

     

    As an aside, you'll have to forgive me if I don't rely on your explanation of the realms of language and logic.

     

    Dave Watts, CTO, Fig Leaf Software

     
    |
    Mark as:
  • Currently Being Moderated
    Feb 26, 2012 1:24 PM   in reply to Dave Watts

    Dave Watts wrote:

     

    There is no context in which uniqueness and randomness mean the same thing.

    This statement is of course untrue. You state, but fail to expound. By beef, I meant you could, for example, expound on the lack of equivalence between uniqueness and randomness in a few contexts of your own choosing.

     

    You mentioned the random number generator, so we're in the domain of mathematics, computing, physics and logic. Take your pick. You may want to show the lack of equivalence between uniqueness and randomness in the sense of Gauss, Lyapunov or Kolmogorov, in the sense of Turing and predicate logic, or in the sense of Markov, Wiener or chaotic dynamics.

     

    Above, I explained a context in which uniqueness implies randomness, and where randomness implies uniqueness. Equivalence follows. It may also be that I'm wrong. However, if you do not come up with a substantial argument, then we should just agree to differ and leave it at that.

     
    |
    Mark as:
  • Currently Being Moderated
    Feb 26, 2012 1:29 PM   in reply to Dave Watts

    Dave Watts wrote:

     

    it's a very simple thing.

    Randomness and uniqueness?  There are loads of unsolved problems on these themes, in the areas of Mathematics, Logic and Computing!

     
    |
    Mark as:
  • Currently Being Moderated
    Feb 26, 2012 1:34 PM   in reply to BKBK

    Wiener

     

    Well you're definitely being one of those.

     

    ;-)

     

    --

    Adam

     
    |
    Mark as:
  • Dave Watts
    747 posts
    Mar 11, 2003
    Currently Being Moderated
    Feb 26, 2012 1:47 PM   in reply to BKBK

    Above, I explained a context in which uniqueness implies randomness, and where randomness implies uniqueness. Equivalence follows. It may also be that I'm wrong. However, if you do not come up with a substantial argument, then we should just agree to differ and leave it at that.

     

    Mutual implication between two things does not make them equivalent, no matter how much you seem to think it does, and no matter what context you explain. I don't see how an argument can be more substantial than one that relies on the plain meaning of two words.

     

    Dave Watts, CTO, Fig Leaf Software

     
    |
    Mark as:
  • Currently Being Moderated
    Feb 26, 2012 1:55 PM   in reply to Adam Cameron.

    Adam Cameron. wrote:

     

    Wiener

     

    Well you're definitely being one of those.

     

    ;-)

     

    I'm not worthy.

     

    Norbert Wiener:

         - graduated from high school at 11

         - obtained a degree in Mathematics at 14

         - obtained a Ph.D. from Harvard at 17

         - made significant contributions in computing, robotics, mathematics, physics, logic, biology, just to name some.

     
    |
    Mark as:
  • Currently Being Moderated
    Feb 26, 2012 1:59 PM   in reply to Dave Watts

    BKBK wrote:

    Above, I explained a context in which uniqueness implies randomness, and where randomness implies uniqueness. Equivalence follows. It may also be that I'm wrong. However, if you do not come up with a substantial argument, then we should just agree to differ and leave it at that.

     

    Dave Watts wrote:

     

    Mutual implication between two things does not make them equivalent, no matter how much you seem to think it does, and no matter what context you explain.

    You are again wrong. If x implies y and y implies x, then x is equivalent to y (at least in the contexts of mathematics, computation and logic).

     
    |
    Mark as:
  • Dave Watts
    747 posts
    Mar 11, 2003
    Currently Being Moderated
    Feb 26, 2012 2:02 PM   in reply to BKBK

    Dave Watts wrote:

     

    Mutual implication between two things does not make them equivalent, no matter how much you seem to think it does, and no matter what context you explain.

    You are again wrong. If x implies y and y implies x, then x is equivalent to y (at least in the contexts of mathematics, computation and logic).

     

    Words are not numeric expressions. Sentences are not solvable equations.

     

    Dave Watts, CTO, Fig Leaf Software

     
    |
    Mark as:
  • Currently Being Moderated
    Feb 26, 2012 2:12 PM   in reply to Dave Watts

     

    Dave Watts wrote:

     

    Mutual implication between two things does not make them equivalent, no matter how much you seem to think it does, and no matter what context you explain.

     

    BKBK wrote:

     

    You are again wrong. If x implies y and y implies x, then x is equivalent to y (at least in the contexts of mathematics, computation and logic).

     

     

    Dave Watts wrote:

     

    Words are not numeric expressions. Sentences are not solvable equations.

    That statement doesn't only apply to numeric expressions. It is a universally accepted fact in logic.

     

    So, let me oblige, using sentences. If one sentence implies another, and the second implies the first, then the 2 sentences are equivalent.

     
    |
    Mark as:
  • Dave Watts
    747 posts
    Mar 11, 2003
    Currently Being Moderated
    Feb 26, 2012 2:34 PM   in reply to BKBK

    That statement doesn't only apply to numeric expressions. It is a universally accepted fact in logic.

     

    So, let me oblige, using sentences. If one sentence implies another, and the second implies the first, then the 2 sentences are equivalent.

     

    This is where I sighed, but I guess you couldn't hear that.

     

    Here is a very simple counterexample. One sentence can, of course, imply more than one thing. If one sentence implies a second and a third, and the second implies the first but not the third, they are clearly not equivalent. What you presumably meant was that if x implies y and only implies y, and vice-versa, then they are equivalent. Of course, that rarely happens with sentences that have any complexity at all. When it happens with words, we call those words "synonyms". So, again, mutual implication, alone, between two things does not make them equivalent.

     

    Now, going back to the item in question. Here is your quote from a previous post:

     

    "In the above context (of CFToken) uniqueness and randomness are synonymous. They are both measures of the effectiveness of the random generator. In this sense, uniqueness means that, if you pick one CFToken from an extremely large list of CFTokens generated by ColdFusion, the probability of there being another one identical to it is negligible. Randomness means, if you pick any arbitrary number of consecutive CFTokens in the list,  you will be unable to find an algorithm to use them to predict the next one."

     

    This set of sentences contradict each other. Just because two things are required for a third thing, that does not mean that those two things are synonymous. And, in fact, you acknowledge that by GIVING DIFFERENT DEFINITIONS FOR THOSE TWO THINGS. Those two sentences DO NOT MEAN THE SAME THING. If they did, you could swap their definitional clauses like so:

     

    "uniqueness means that, if you pick any arbitrary number of consecutive CFTokens in the list,  you will be unable to find an algorithm to use them to predict the next one."

     

    "randomness means that, if you pick one CFToken from an extremely large list of CFTokens generated by ColdFusion, the probability of there being another one identical to it is negligible."

     

    Now, I notice that you did not do this. And, I suspect, you would not be inclined to say that you can, in fact, do this. That is because the two words mean different things, even in the context in which you used them.

     

    Dave Watts, CTO, Fig Leaf Software

     
    |
    Mark as:
  • Currently Being Moderated
    Feb 26, 2012 3:39 PM   in reply to Dave Watts

    I see no development or new idea beyond my own, so I'll end here.

     
    |
    Mark as:
  • Dave Watts
    747 posts
    Mar 11, 2003
    Currently Being Moderated
    Feb 26, 2012 3:53 PM   in reply to BKBK

    Your "new idea" seems to be that you can define words however you like, as Humpty-Dumpty would. So perhaps it's best you end here.

     

    Dave Watts, CTO, Fig Leaf Software

     
    |
    Mark as:
  • Currently Being Moderated
    Feb 27, 2012 12:03 AM   in reply to Dave Watts

    Dave Watts wrote:

     

    Your "new idea" seems to be that you can define words however you like, as Humpty-Dumpty would.

    When the insults start flying in, then it often means the ideas are used up. Incidentally, I expected better from a Community Pro.

     

    Why only settle on "new idea"? I gave you quite some leeway with "development or new idea". Also, you could have gone for "is" in place of "seems to be". So why the timidity? Let me guess. Because you have difficulty substantiating your arguments?

     

    Unlike you, I care about the quality of my argumentation. In my opinion, yours has been below par, in this thread in any case. As far as this line of argument goes, I will definitely end here.

     
    |
    Mark as:
  • Dave Watts
    747 posts
    Mar 11, 2003
    Currently Being Moderated
    Feb 27, 2012 7:08 AM   in reply to BKBK

    When the insults start flying in, then it often means the ideas are used up. Incidentally, I expected better from a Community Pro.

     

    You seem to be defining words however you like, and that's what I said. That is not intended to be an insult, merely an observation. I think that, in general, you are a valuable contributor here. But that doesn't mean that words just mean what you say they do.

    Why only settle on "new idea"? I gave you quite some leeway with "development or new idea". Also, you could have gone for "is" in place of "seems to be". So why the timidity? Let me guess. Because you have difficulty substantiating your arguments?

     

    I went with "seems to be" because I like to extend people the benefit of the doubt. I settled on "new idea" because I didn't see any "development" in any case. I think I substantiated my argument as clearly as possible. To return to that, would you accept the alternative definitions I propsed earlier?

     

    "uniqueness means that, if you pick any arbitrary number of consecutive CFTokens in the list,  you will be unable to find an algorithm to use them to predict the next one."

     

    "randomness means that, if you pick one CFToken from an extremely large list of CFTokens generated by ColdFusion, the probability of there being another one identical to it is negligible."

     

    If you do accept them, then you clearly think that the two words are synonymous, and that is that. I'd disagree, but we'd probably get no farther. If you don't accept them, however, then you clearly don't think the two words are synonymous. You never did respond to this very specific point. I'm not going to speculate on why you didn't, but I think this is a substantial argument and worthy of an honest, clear response.

     

    Unlike you, I care about the quality of my argumentation. In my opinion, yours has been below par, in this thread in any case.

     

    Now that seems to be more than you can accurately speculate on - you have no idea what is in my mind, do you? No? I didn't think so. In fact, I care very much about how words are used. Words have meanings. I get quite riled up when people just use them any old way, like you, in my opinion, did earlier in the thread. I will discount your opinion about the quality of my argumentation as a result, until you can respond to the very specific question I posed earlier.

     

    Dave Watts, CTO, Fig Leaf Software

     
    |
    Mark as:
  • Currently Being Moderated
    Feb 27, 2012 7:24 AM   in reply to Dave Watts

    Dave Watts wrote:

     

    When the insults start flying in, then it often means the ideas are used up. Incidentally, I expected better from a Community Pro.

     

    You seem to be defining words however you like, and that's what I said. That is not intended to be an insult, merely an observation. I think that, in general, you are a valuable contributor here. But that doesn't mean that words just mean what you say they do.

    Why only settle on "new idea"? I gave you quite some leeway with "development or new idea". Also, you could have gone for "is" in place of "seems to be". So why the timidity? Let me guess. Because you have difficulty substantiating your arguments?

     

    I went with "seems to be" because I like to extend people the benefit of the doubt. I settled on "new idea" because I didn't see any "development" in any case. I think I substantiated my argument as clearly as possible. To return to that, would you accept the alternative definitions I propsed earlier?

     

    "uniqueness means that, if you pick any arbitrary number of consecutive CFTokens in the list,  you will be unable to find an algorithm to use them to predict the next one."

     

    "randomness means that, if you pick one CFToken from an extremely large list of CFTokens generated by ColdFusion, the probability of there being another one identical to it is negligible."

     

    If you do accept them, then you clearly think that the two words are synonymous, and that is that. I'd disagree, but we'd probably get no farther. If you don't accept them, however, then you clearly don't think the two words are synonymous. You never did respond to this very specific point. I'm not going to speculate on why you didn't, but I think this is a substantial argument and worthy of an honest, clear response.

     

    Unlike you, I care about the quality of my argumentation. In my opinion, yours has been below par, in this thread in any case.

     

    Now that seems to be more than you can accurately speculate on - you have no idea what is in my mind, do you? No? I didn't think so. In fact, I care very much about how words are used. Words have meanings. I get quite riled up when people just use them any old way, like you, in my opinion, did earlier in the thread. I will discount your opinion about the quality of my argumentation as a result, until you can respond to the very specific question I posed earlier.

     

    Dave Watts, CTO, Fig Leaf Software

    Seen, but not read.

     
    |
    Mark as:
  • Currently Being Moderated
    Feb 27, 2012 7:42 AM   in reply to BKBK

    Seen, but not read.

     

    This is hilarious.  You're basically stooping to the level of "I know you are, you said you are, but what am I?".  If Dave was a girl, you'd've pulled his hair and run off by now.

     

    Why don't you just concede "yeah, good point Dave"?

     

    Surely that's easier that the lengths you have gone to to demonstrate a) how foolish you are; b) how you don't get that just conceding being wrong is far less "bad" (if it even is "bad") than making a complete jack-*** out of yourself.  Why would you rather look like a complete *** than just admit you were wrong?

     

    But do continue... this is fun...

     

    --

    Adam

     
    |
    Mark as:
  • Currently Being Moderated
    Feb 27, 2012 8:07 AM   in reply to Adam Cameron.

    Adam Cameron. wrote:

     

    Seen, but not read.

     

    This is hilarious.  You're basically stooping to the level of "I know you are, you said you are, but what am I?".  If Dave was a girl, you'd've pulled his hair and run off by now.

     

    Why don't you just concede "yeah, good point Dave"?

     

    Surely that's easier that the lengths you have gone to to demonstrate a) how foolish you are; b) how you don't get that just conceding being wrong is far less "bad" (if it even is "bad") than making a complete jack-*** out of yourself.  Why would you rather look like a complete *** than just admit you were wrong?

     

    But do continue... this is fun..

    I saw, and read, this one. Easy just to keep saying I'm wrong, isn't it? Please do rally together and prove me wrong.

     

    Added edit: I am a mathematician by training, so I wont resist the temptation of inviting you both to define the 'randomness' and 'uniqueness' you claim to know so much about. Your contribution on the subject so far is nothing to write home about.

     
    |
    Mark as:
  • Currently Being Moderated
    Feb 27, 2012 8:07 AM   in reply to BKBK

     

    Seen, but not read.

     

    This is hilarious.  You're basically stooping to the level of "I know you are, you said you are, but what am I?".  If Dave was a girl, you'd've pulled his hair and run off by now.

     

    Why don't you just concede "yeah, good point Dave"?

     

    Surely that's easier that the lengths you have gone to to demonstrate a) how foolish you are; b) how you don't get that just conceding being wrong is far less "bad" (if it even is "bad") than making a complete jack-*** out of yourself.  Why would you rather look like a complete *** than just admit you were wrong?

     

    But do continue... this is fun..

    I saw, and read, this one. Easy just to keep saying I'm wrong. Please do rally together and prove me wrong.

     

    But this has already been done, both by Jason and by Dave in their initial posts in response to your assertion.  Plain and simple "randomness" and "uniqueness" are not - in any way - equivalent notions.  Not in the context of CFTOKENs, and not in any other context either.  You can spout as much meaningless babble as you like, but that's all anything you have said has been: meaningless babble.  It's not an argument.  It's not a position.  You have not put forward a case of any description.  There is not even anything approaching logic to it.  You've said nothing that can be "proved" one way or the other, because on the whole, nothing you have said has made any sense.  It's just incoherent nonsense.  It's so much to that extent that if I didn't know better (due to the last time I indicated that was my suspicion, and you corrected me), I'd again be asking whether English is your first language.

     

    The only thing you have done (and are continuing to do ~) is made yourself look a bit silly.

     

    --

    Adam

     
    |
    Mark as:
  • Currently Being Moderated
    Feb 27, 2012 9:25 AM   in reply to Adam Cameron.

    Adam Cameron. wrote:

     

    Plain and simple "randomness" and "uniqueness" are not - in any way - equivalent notions.  Not in the context of CFTOKENs, and not in any other context either.

    I have extracted what I consider to be the essence of the matter. I hope everyone will agree that such a statement is meaningless unless the author first tells us what he means by "randomness" and "uniqueness". You don't. Neither did Dave before you.

     

    Instead you hide behind a smokescreen of insults and trivial, half-baked ideas. Let's get back to basics. Here again is my attempt at establishing the context in which I said uniqueness is equivalent to randomness:

     

    Uniqueness: If you pick one CFToken from an extremely large list of CFTokens generated by ColdFusion, the probability of there being another one identical to it is negligible.

     

    Randomness: If you pick any arbitrary number of consecutive CFTokens in the list, you will be unable to find an algorithm to use them to predict the next one.

     

    I may or may not be right, but that is another matter. I have at least put up. Whereas, you and Dave criticize and criticize, without ever once telling the forum what you understand by randomness or uniqueness.

     

    So let's skip the chase. Tell us what you mean by "randomness" and "uniqueness". In any context you choose to name. If what I've seen so far is anything to go by, we'll be waiting here till we begin to grow feathers.

     
    |
    Mark as:
  • Currently Being Moderated
    Feb 27, 2012 9:26 AM   in reply to Adam Cameron.

    Adam Cameron wrote:

     

    It's so much to that extent that if I didn't know better (due to the last time I indicated that was my suspicion, and you corrected me), I'd again be asking whether English is your first language.

     

     

    What's your obsession about English as a first language? From a New Zealander at that!

     

    Wisen up, man. There are dozens of different official English dialects in the world. Nationals from Nigeria, Trinidad, Saint Lucia and Russia, whose first language wasn't English, have gone on to win the Nobel Prize in English Literature.

     

    To return to the point, this is an international forum. It is sufficient to be understood. We owe it to each other to make allowances for  differences in nationality and language.

     

    I know that you have a reputation to keep as a bully in these forums. Of course, whenever you were spoiling for a fight, I succeeded in flooring you, every time.  There wont be an exception this time. I'll repeat what I told you on the previous occasion you mention. Continually making snide remarks on another visitor's language level simply shows you lack manners.

     
    |
    Mark as:
  • Currently Being Moderated
    Feb 28, 2012 2:40 AM   in reply to BKBK

     

    Adam Cameron. wrote:

     

    Plain and simple "randomness" and "uniqueness" are not - in any way - equivalent notions.  Not in the context of CFTOKENs, and not in any other context either.

    I have extracted what I consider to be the essence of the matter.

     

    [...]

     

    Uniqueness: If you pick one CFToken from an extremely large list of CFTokens generated by ColdFusion, the probability of there being another one identical to it is negligible.

     

    Randomness: If you pick any arbitrary number of consecutive CFTokens in the list, you will be unable to find an algorithm to use them to predict the next one.

     

     

     

    Which - by your own description (which is adequate) - demonstrates they are not related concepts, and attempt to achieve different ends.

     

    Let's clarify this outwith the context of CF.

     

    Randomness.  A series of values is random if the next value cannot be inferred from the previous values (in part or as a whole), and no previous values have any influence over subsequent values.  A measure of the randomness of an algorithm is how well it fulfils that criteria.

     

    Uniqueness.  A value within a series is unique if it occurs only once.  A measure how well an algorithm provides unique results is in what the probability of getting duplicate results is.

     

    To demonstrate how these concepts are very different let's look at some test results from within a small system

     

    Say the system has a range of 1000 possible values, and we take ten samples.  And the algorithms are "perfect".

     

    The random sample could be:

    500, 123, 666, 42, 1, 789, 501, 42, 317, 256.

     

    Note that 42 has - completely randomly - occurred twice.  In fact just as random as the result above, would be this result:

    1, 1, 1, 1, 1, 1, 1, 1, 1, 1

     

    That is no less likely to be the result than the seemingly more random one.

     

    If we extend this out to be 1000 samples, there is an equal chance of any given element having the same value as one other element as there is for it to be any other specific number.

     

    Duplicates are part and parcel, and completely "expected" in random number series.

     

    On the other hand, a unique algorithm "guarantees" (for all intents and purposes) that the results are... well... unique.

     

    In the 1000-item example, a completely legit uniqueness algorithm might be to simply increment a counter:

    1,2,3,4,5,6,7,8,9,10.

     

    (and this algorithm still works perfectly right out to the full 1000 item sample size).

     

    There is no randomness there (randomness is not part of the remit of a uniqueness algorithm), and it is entirely predictable (lack of predictability is not part of the remit of a uniqueness algorthim).  Also a preceding result directly inflences the next result (the next being an increment of the previous).

     

    So this in itself demonstrates that randomness and uniqueness are very different qualities, and differ significantly when it comes to the qualities that each are measured by (predictability, and how much one value influences another).

     

    When it comes to real-world examples, UUIDs can be generated in a completely predictable fashion.  The composition of a UUID could be:

    * MAC address of a NIC in the box generating the UUID

    * the time down to some arbitrary accuracy (the one I looked at was down to 100ns)

    * a correction value (should the time be adjusted backwards between one UUID and the next)

    * a counter (to allow for UUIDs to be generated faster than the accuracy of the clock)

     

    If one presupposes that a MAC address is adequate to be a unique spatial identifier, and the correction values and counter are large enough to not overflow, then this will generate unique values, and not be at all random.

     

    If one was not satisfied with the MAC solution, and technology was slightly better than we currently have, a "perfect" uniqueness algorithm could be implemented using the geolocation of the machine running the algorithm (accurate to a degree smaller than the size of the machine, so it guarantees no machines can have a same value), and a time clock more accurate than the time it takes to generate a result (so every result from a given machine occurs at a different time). The unique value then is simply machine location + current time.

     

    Really the only similarity between the two concepts is that both use an algorithm, and both provide results. Beyond that, they are mostly disconnected concepts.

     

    Is that enough?  Although your own example was, as I said, good enough to contradict what you're saying.

     

    --

    Adam

     
    |
    Mark as:
  • Currently Being Moderated
    Feb 28, 2012 2:46 AM   in reply to BKBK

     

    It's so much to that extent that if I didn't know better (due to the last time I indicated that was my suspicion, and you corrected me), I'd again be asking whether English is your first language.

     

     

    What's your obsession about English as a first language? From a New Zealander at that!  

     

     

    You have the wrong end of the stick.  I have no problem - nor have I ever demonstrated to have one (or I'm sorry if I did, it was not my intent at all) - with people who have English as a second language.  Most people, after all, do not have English as their primary language.

     

    What I was saying is that in some situations - this current thread for example -  you communicate like English is not your native language, which is odd, given you claim that it is.  That's all I meant.

     

    If English wasn't your primary language, you make a pretty good fist of communicating in it.  If it is your first language (you have claimed that it is, and I have no reason to doubt you), then you tend to write fairly incoherently at times: it has a tendency to come across as if you don't quite understand the words you're using (in the context you're using them), and often what you say seems unrelated to the subject at hand.

     

    --

    Adam

     
    |
    Mark as:
  • Currently Being Moderated
    Feb 29, 2012 12:55 AM   in reply to Adam Cameron.

    Adam Cameron. wrote:

     

     

    You have the wrong end of the stick.  I have no problem - nor have I ever demonstrated to have one (or I'm sorry if I did, it was not my intent at all) - with people who have English as a second language.  Most people, after all, do not have English as their primary language.

     

    What I was saying is that in some situations - this current thread for example -  you communicate like English is not your native language, which is odd, given you claim that it is.  That's all I meant.

     

    If English wasn't your primary language, you make a pretty good fist of communicating in it.  If it is your first language (you have claimed that it is, and I have no reason to doubt you), then you tend to write fairly incoherently at times: it has a tendency to come across as if you don't quite understand the words you're using (in the context you're using them), and often what you say seems unrelated to the subject at hand.

     

    As anyone can see, except you, of course, your argumentation is rather weak. You tell me I have the wrong end of the stick, but then go on to apologize. I have the right end of the stick, and the word "obsession" is the correct chioce. As I said, there is a precedent in this rude behaviour of yours.

     

    This is a ColdFusion forum. The business is ColdFusion. If a fellow visitor says something that is unclear, or even meaningless, the expectation is that suggestions will aim to point out what was unclear or meaningless. The whole point is to be understood.

     

    However, that isn't the case with your obsession. You simply appear to derive a sense of superiority or some smug satisfaction in embarassing another visitor. Neither you nor anyone else should take my word for it. This forum is universally available on the web. Your intention is there for anyone to see.

     

    The mere fact of commenting on someone else's language level is already a tad insensitive. Yet you have done this repeatedly, by your own admission, returning again and again to the subject.

     

    On a previous occasion, you went as far as to mention that I am a Dutch national, and even that I had supplied that information. I let you know you were wrong. Did you stop there? No.

     

    Now you say I have claimed English is my native language. Well, I didn't tell you it was. Neither did I tell you it wasn't. What I told you, and I am doing so again in this thread, is that that information is irrelevant in a ColdFusion forum and will remain private, especially given the rude and obsessive manner in which you keep bringing it up.

     

    I can guess where the obsession comes from. You come over as uncouth in manner, a bully and someone who overrates himself. I have always resisted the temptation of stooping to your level, and returning your insults and snide remarks. Like all bullies you seem to misinterprete this as weakness. In spite of the intellectual beating you've received from me over the years. But then again, bullies are known for lacking the emotional intelligence to remember the last time they received a black eye. Which is why they frequently have one.

     

    You've succeeded in browbeating quite a number of visitors in the ColdFusion forums. However, whenever you've tried to mix it up with me, I've floored you each and every time.  As I promised you earlier in this thread, there wont be an exception this time.

     
    |
    Mark as:
  • Currently Being Moderated
    Feb 29, 2012 12:59 AM   in reply to BKBK

    I like turtles.

     
    |
    Mark as:
  • Currently Being Moderated
    Feb 29, 2012 3:42 AM   in reply to Adam Cameron.

    Adam Cameron. wrote:

     

    your own description (which is adequate)

     

    Thanks. Sincerely. It wouldn't have been easy for you. It's quite a U-turn for the man who told me just a moment ago:

     

    on the whole, nothing you have said has made any sense.  It's just incoherent nonsense.

     
    |
    Mark as:
1 2 Previous Next
Actions

More Like This

  • Retrieving data ...

Bookmarked By (0)

Answers + Points = Status

  • 10 points awarded for Correct Answers
  • 5 points awarded for Helpful Answers
  • 10,000+ points
  • 1,001-10,000 points
  • 501-1,000 points
  • 5-500 points