The scan will be broken up into multiple map tasks, each of which will run over a single split of the table (look at TableInputFormat to see how it is done). The map tasks will run in parallel.
Jeff On Tue, Aug 20, 2013 at 8:45 AM, yonghu <yongyong...@gmail.com> wrote: > Hello, > > I know if I use default scan api, HBase scans table in a serial manner, as > it needs to guarantee the order of the returned tuples. My question is if I > use MapReduce to read the HBase table, and directly output the results in > HDFS, not returned back to client. The HBase scan is still in a serial > manner or in this situation it can run a parallel scan. > > Thanks! > > Yong > -- *Jeff Kolesky* Chief Software Architect *Opower*
