For an easy solution, use hive. Let's say your record contains userid and friendid and the table is called friends Then you would do select A.userid , B.friendid from friends A join friends B on (A.friendid = B user.id)
This is on top of my mind, sorry if some details are off, but I've done it in the past on large datasets (~100M rows).That's it. Do that in java and tell me if it isn't at least 50 lines of code. A On Sun, Dec 19, 2010 at 6:28 PM, Praveen Bathala <pbatha...@gmail.com>wrote: > Hi, > > I am trying to write a MapReduce code to find friends of friends in a > social network with MapReduce. > my data snippet : > > 1 41 > 1 7 > 1 100 > 2 64 > 2 65 > 2 42 > 2 86 > 3 54 > 3 24 > 3 16 > 3 43 > 4 39 > 4 52 > > Here map() goes through line by line, now I get "41" as friend to "1" and I > want to go to all "41"'s to get his friends. how can I do that. > Can I jump to any line I need in Mapper class? > > Please, Help me with this... > > Thanks in advance > + Praveen
