Ted, I am also interested in this answer.
I put the name of a zip file on a line in an input file, and I want one mapper to read this line, and start working on it (since it now knows the path in HDFS). Are you saying it's not doable? Thank you, Mark On Mon, Feb 7, 2011 at 8:10 PM, Ted Dunning <tdunn...@maprtech.com> wrote: > Option (1) isn't the way that things normally work. Besides, mappers are > called many times for each construction of a mapper. > > On Mon, Feb 7, 2011 at 3:38 PM, maha <m...@umail.ucsb.edu> wrote: > > > Hi, > > > > I would appreciate it if you could give me your thoughts if there is > > affect on efficiency if: > > > > 1) Mappers were per line in a document > > > > or > > > > 2) Mappers were per block of lines in a document. > > > > > > I know the obvious difference I can see is that (1) has more mappers. > Does > > that mean (1) will be slower because of scheduling time ? > > > > Thank you, > > Maha > > >