Binning time
Thursday, February 24, 2011
12:30 PM
Our schema is now
posts: (time:long, user:chararray)
We are interested in "buzz" events, which are negative posts by multiple users at roughly the same time. 
First, we select a time interval (e.g., one hour=3600 seconds) and create timestamps every hour:
clusters = FOREACH posts GENERATE time-time%3600 as time, user;
We are only interested in how many distinct users are involved, so
cluster2 = DISTINCT clusters; 
So far, our schema hasn't changed:
cluster2: (time:long, user:chararray); 