Pavan: Did you use TableInputFormat or its variant ? If so, take a look at TableSplit and how it is used in TableInputFormatBase#getSplits().
Cheers On Sun, Aug 25, 2013 at 2:36 PM, Jens Scheidtmann < [email protected]> wrote: > Hi Pavan, > > >> 2. ) If my table is in the order of millions, the number of mappers is >> increased to 5.. How does Hadoop know how many mappers to run for a >> specific job? >> >> The number of input splits determines the number of mappers. Usually (in > the default case) your source is split into hdfs blocks (usually 64 MB) and > for each block, there will be a mapper. > > Best regards, > > Jens > >
