For that do we have to write a custom class for value inorder to pass all the columns as value. ie in the example 2 values. Or jst do a concatenation and emit values.
On Sat, Jan 11, 2014 at 9:46 PM, Chris Mawata <[email protected]>wrote: > Results will be sorted by key so make A the key and put the rest in the > value > Chris > On Jan 11, 2014 10:11 AM, "unmesha sreeveni" <[email protected]> > wrote: > >> What about sorting . >> Acutually it is done by MapReduce itself. >> But if we are giving a csv file as input and trying to sort one/multiple >> column...Whether the corresponting columns also get reflectted?? >> >> eg: foo.csv >> B,2,3 >> A,4,6 >> >> When we apply sorting to first column:whether the resultent will be >> A,4,6 >> B,2,3 >> A will be mapped to its correct values right? >> If so what will be context.write() of mapper? >> >> >> On Wed, Jan 8, 2014 at 8:18 PM, Chris Mawata <[email protected]>wrote: >> >>> Yes. >>> Check out, for example, >>> http://packtlib.packtpub.com/library/hadoop-mapreduce-cookbook/ch06lvl1sec66# >>> >>> >>> >>> On 1/8/2014 2:41 AM, unmesha sreeveni wrote: >>> >>> Can we do aggregation with in Hadoop MR >>> like find min,max,sum,avg of a column in a csv file. >>> >>> -- >>> *Thanks & Regards* >>> >>> Unmesha Sreeveni U.B >>> Junior Developer >>> >>> http://www.unmeshasreeveni.blogspot.in/ >>> >>> >>> >>> >> >> >> -- >> *Thanks & Regards* >> >> Unmesha Sreeveni U.B >> Junior Developer >> >> http://www.unmeshasreeveni.blogspot.in/ >> >> >> -- *Thanks & Regards* Unmesha Sreeveni U.B Junior Developer http://www.unmeshasreeveni.blogspot.in/
