This approach may not combine the results as per the key to reduce function.
-----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Miles Osborne Sent: Thursday, July 09, 2009 10:03 AM To: [email protected] Subject: Re: Sort by value if you have <key,value> pairs, then have your mapper emit <value,<key,value>> this will result in your data being resorted by the value Miles 2009/7/9 Marcus Herou <[email protected]> > Really ? WIll that work ? > > input something like this > > tag > tag2 > tag > tag2 > tag3 > ... > produces output > > tag 2 > tag2 2 > tag3 1 > .... > > Swapping key/value will then map all 2's to what ? > > > > On Thu, Jul 9, 2009 at 4:53 PM, jason hadoop <[email protected]> > wrote: > > > The simplest way is to swap the key and value in your mapper's output, > then > > swap them back afterward. > > > > On Thu, Jul 9, 2009 at 7:52 AM, Marcus Herou <[email protected] > > >wrote: > > > > > Hi many times I want to sort by value instead of key. > > > > > > For instance when counting the top used tags in blog posts or the ten > > most > > > visited pages on a certain site and so on. > > > > > > Wondering if that is even possible with hadopp or if I need to process > > the > > > file outside of hadoop. > > > > > > Cheers > > > > > > /Marcus > > > > > > -- > > > Marcus Herou CTO and co-founder Tailsweep AB > > > +46702561312 > > > [email protected] > > > http://www.tailsweep.com/ > > > > > > > > > > > -- > > Pro Hadoop, a book to guide you from beginner to hadoop mastery, > > http://www.amazon.com/dp/1430219424?tag=jewlerymall > > www.prohadoopbook.com a community for Hadoop Professionals > > > > > > -- > Marcus Herou CTO and co-founder Tailsweep AB > +46702561312 > [email protected] > http://www.tailsweep.com/ > -- The University of Edinburgh is a charitable body, registered in Scotland, with registration number SC005336.
