In reduce() we have: key1 values1 key2 values2 ... keyn valuesn
so,what i want to do is join all values like a SQL: select * from values1,values2...valuesn; if memory is not enough to cache values,how to complete the join operation? my idea is clone the reducecontext,but it maybe not easy. Any help will be appreciated. 2013/3/13 Roth Effy <[email protected]> > I want a n:n join as Cartesian product,but the DataJoinReducerBase looks > like only support equal join. > I want a non-equal join,but I have no idea now. > > > 2013/3/13 Azuryy Yu <[email protected]> > >> you want a n:n join or 1:n join? >> On Mar 13, 2013 10:51 AM, "Roth Effy" <[email protected]> wrote: >> >>> I want to join two table data in reducer.So I need to find the start of >>> the table. >>> someone said the DataJoinReducerBase can help me,isn't it? >>> >>> >>> 2013/3/13 Azuryy Yu <[email protected]> >>> >>>> you cannot use RecordReader in Reducer. >>>> >>>> what's the mean of you want get the record position? I cannot >>>> understand, can you give a simple example? >>>> >>>> >>>> On Wed, Mar 13, 2013 at 9:56 AM, Roth Effy <[email protected]> wrote: >>>> >>>>> sorry，I still can't understand how to use recordreader in the >>>>> reduce(),because the input is a RawKeyValueIterator in the class >>>>> reducecontext.so,I'm confused. >>>>> anyway,thank you. >>>>> >>>>> >>>>> 2013/3/12 samir das mohapatra <[email protected]> >>>>> >>>>>> Through the RecordReader and FileStatus you can get it. >>>>>> >>>>>> >>>>>> On Tue, Mar 12, 2013 at 4:08 PM, Roth Effy <[email protected]>wrote: >>>>>> >>>>>>> Hi,everyone, >>>>>>> I want to join the k-v pairs in Reduce(),but how to get the record >>>>>>> position? >>>>>>> Now,what I thought is to save the context status,but class Context >>>>>>> doesn't implement a clone construct method. >>>>>>> >>>>>>> Any help will be appreciated. >>>>>>> Thank you very much. >>>>>>> >>>>>> >>>>>> >>>>> >>>> >>> >
