On Apr 11, 2014, at 8:54 AM, Peter Levart <peter.lev...@gmail.com> wrote: > > Hi, > > Code that relies on UUIDs to have a "natural" order, say "chronological", is > relying on being given the particular type of UUIDs that have the time > built-in. When given mixed-type or non-time-based UUIDs, such code will > break. The purpose of UUID schemes is generating globally unique identifiers, > not interpreting them. Various types exist just because it's practical to > generate UUIDs differently in different contexts.
Good point, the bias is towards producers, but still i can imagine time-based UUIDs are quite useful for consumers and i think implicitly such users would reasonably expect them to be ordered in some manner based on the time. > Programs should not try to extract business information from UUIDs (except > probably for hunting down virus authors: > http://en.wikipedia.org/wiki/Melissa_%28computer_virus%29). So I think a good > general-purpose compareTo() method should try to discourage such usage for > example by reversing the bits of the UUID value before comparing. This would > also make algorithms that order UUIDs for facilitating quick access (B-Tree, > Red-Black-Tree, ...) happier. > Interesting, i suppose if those N values are randomly shuffled then added it may get close to reversed bit result, i should probably try it :-) Paul.
