Re: Can hadoop sort by values rather than keys?
Might be able to use InverseMapper.class To help flip the key/value to value/key Billy "Jeremy Chow" <[EMAIL PROTECTED]> wrote in message news:[EMAIL PROTECTED] Hi list, The default way hadoop doing its sorting is by keys , can it sort by values rather than keys? Regards, Jeremy -- My research interests are distributed systems, parallel computing and bytecode based virtual machine. http://coderplay.javaeye.com
Re: Can hadoop sort by values rather than keys?
Sorting according to keys is a requirement for the map/reduce algorithm. I'd suggest running a second map/reduce phase on the output files of your application and use the values as keys in that second phase. I know that will increase the running time, but this is how I do it when I need to get my output files sorted according to their values rather then keys. Jim On Wed, Sep 24, 2008 at 9:28 PM, Qin Gao <[EMAIL PROTECTED]> wrote: > Why not use the value as keys. > > On Wed, Sep 24, 2008 at 10:22 PM, Jeremy Chow <[EMAIL PROTECTED]> wrote: > > > Hi list, > > The default way hadoop doing its sorting is by keys , can it sort by > > values rather than keys? > > > > Regards, > > Jeremy > > -- > > My research interests are distributed systems, parallel computing and > > bytecode based virtual machine. > > > > http://coderplay.javaeye.com > > >
Re: Can hadoop sort by values rather than keys?
Why not use the value as keys. On Wed, Sep 24, 2008 at 10:22 PM, Jeremy Chow <[EMAIL PROTECTED]> wrote: > Hi list, > The default way hadoop doing its sorting is by keys , can it sort by > values rather than keys? > > Regards, > Jeremy > -- > My research interests are distributed systems, parallel computing and > bytecode based virtual machine. > > http://coderplay.javaeye.com >
Can hadoop sort by values rather than keys?
Hi list, The default way hadoop doing its sorting is by keys , can it sort by values rather than keys? Regards, Jeremy -- My research interests are distributed systems, parallel computing and bytecode based virtual machine. http://coderplay.javaeye.com
