On Fri, Feb 27, 2009 at 8:23 AM, Paul Davis <paul.joseph.da...@gmail.com> wrote: > On Fri, Feb 27, 2009 at 9:00 AM, Damien Katz <dam...@apache.org> wrote: >> The doc ids can be generated client side, so clients can use any scheme you >> want. For how the server generates UUIDs, there has been some talk about >> doing some work there, but I don't think anyone has started it. >> >> -Damien >> >> >> On Feb 27, 2009, at 7:44 AM, Wout Mertens wrote: >> >>> On Feb 26, 2009, at 8:18 PM, Damien Katz wrote: >>>> >>>> Also, he Ids don't need to be sequential (1,2,3,4...), just ordered >>>> (1,5,19,22...). And they don't need to sort higher or lower than all the >>>> other ids, so long as they are clustered together. The each btree nodes >>>> that have to be loaded that isn't in cache is expensive. The more the keys >>>> have to be inserted into random places in the btree, the worse the caching >>>> behavior. Right now, with the crypto random UUIDs we generate, it's >>>> basically the worst case scenario for doc inserts. >>> >>> So why not decrease security by a tunable factor and add a random number >>> to the previous UUID instead? >>> >>> And while we're on the subject, I've wished for automatic doc UUIDs that >>> nonetheless have a fixed prefix. More human readable plus it doubles as a >>> type field... Any chance of that or is that one of the beginner mistakes? >>> >>> Wout. >> >> > > There was talk of switching the internal uuid generationg to a version > 1 style instead of the version 4 (random) style. My suggestion was to > make the _uuids endpoint accept a v=[1|4] url parameter to choose with > a config file default but people seemed to not like that idea. > > HTH, > Paul Davis >
FWIW (though the opinions of a newbie should be taken with a big brick of salt), I don't mind that the auto-generated UUIDs are "conservative" in their crypto randomness. As a client, I can use whatever scheme I want so it makes sense to go with the most conservative default. And thanks for the very informative answers about btrees everyone. I learned a lot. Cheers, Barry
