> I have 2 question: > 1. Does HBase support scan data of rowkey by column?
You mean secondary indexes? No: http://hbase.apache.org/book.html#secondary.indices > 2. Which design is better? I think that design 2 is better when user have > large amount of follower. I cover a bunch of designs in this very recent thread: http://search-hadoop.com/m/AXRdP1KKR5T1 J-D