В Mon, 7 Nov 2011 11:18:12 +0100 Alain RODRIGUEZ <arodr...@gmail.com> пишет:
> Hi again. > > Did you receive my mail ? It's the first time I use this mailing list. > > If you received it, did anybody face this problem ? > > It looks like this subject is going to be discussed at Cassandra NYC > meeting. > > http://www.datastax.com/2011/11/joe-stein-of-medialets-to-speak-at-cassandra-nyc > > Any idea of what they are going to say about this subject or have I > to wait ? Will the video record of this conference be public ? > > thanks, > > Alain > > 2011/11/4 Alain RODRIGUEZ <arodr...@gmail.com> > > > Hi all, > > > > I started this thread in the phpCassa google group, but I thinks > > its place is here. > > > > There is my first post : > > > > "I was wondering about a specific point of Cassandra Modeling. > > > > If I need to know the number of connexion to my website using each > > browser, every hour, I can do: > > > > Row key: $browser, column key: date('YmdH', $timestamp), value: > > counter. > > > > I can increment this counter for any visit, this should work. The > > point is that I want to be able to render the results of a lot of > > statistics used as filters. > > > > I mean, I will have information such as browser, browser version, > > screen resolution, OS, OS version, localization... And I want to > > allow users to get data (number of views) filtering it as much as > > they want. > > > > For example, if I want to know how many people visited my website > > with safari, windos, and from New York, every hour, I can store: > > > > Row key : $browser:$os:$localization, column key : date('YmdH', > > $timestamp), value : counter. > > > > This can't be the best solution because according to the > > combinational mathematics I will have to store n! counters to be > > able to store data with all filters. If I got 10 filters I will > > increment 3 628 800 counters. > > > > That's not the good solution, for sure. How am I supposed to model > > this to be able to read data with any filter I want ? > > > > Thanks, > > > > Alain" > > > > > > > > And there is the first answer given (thanks to Tyler Hobbs) : > > > > "Technically, the number of potential different counters would be > > the cardinality of each field multiplied together. (Since one of > > the fields holds a time, this number would continue to grow.) > > However, in practice you'll have far fewer than this number of > > counters, because not every possible combination of these will > > happen. > > > > >That's not the good solution, for sure. How am I supposed to model > > > > > this to be able to read data with any filter I want ? > > > > It's a reasonable solution if you want to be able to drill down and > > filter by any attribute. If you want to be able to filter based on > > all of these attributes, you have to store that information about > > every request in one way or another." > > > > > > > > I know it's a non-trivial problem, but I'm sure that some people > > already faced this problem before I do. > > > > I'll allow user to filter however they want, chosing dimensions with > > checkboxes. They will be able to combine dimensions and ask for any > > combination. > > > > So, with this solution, I will have to store every event n times, > > with n = number of possible combinations. > > > > I saw this yesterday : http://t.co/EXL6yAO8 (thanks to Dave > > Gardner). This company seems to something equivalent of the idea > > exposed in my first post.... > > > > Any experience to share with this kind of problem ? > > > > thank you, > > > > Alain > > > > Looks like Your mail has been recieved but for now nowbody has an answer. As for me - I'm a cassandra newbie and definitely can't help :-( Best regards Alexander
