Hi Lefty, I used the wiki you sent to write my first version of UDAF. However, I found it to be utterly complex, especially for storing partial results as I am not very familiar with hive API. Then I found another example of UDAF in the hadoop the definitive guide book and it had much simpler code but using different method. Instead of using iterate it was using evaluate method and so I am getting confused.
Ritesh On Sun, Aug 4, 2013 at 2:18 PM, Lefty Leverenz <leftylever...@gmail.com>wrote: > You might find this wikidoc useful: > GenericUDAFCaseStudy<https://cwiki.apache.org/confluence/display/Hive/GenericUDAFCaseStudy> > . > > The O'Reilly book "Programming Hive" also has a section called > "User-Defined Aggregate Functions" in chapter 13 (Functions), pages 172 to > 176. > > -- Lefty > > > On Sun, Aug 4, 2013 at 7:12 AM, Ritesh Agrawal <ragra...@netflix.com>wrote: > >> Hi all, >> >> I am trying to write a UDAF function. I found an example that shows how >> to implement a UDAF in "Hadoop The Definitive Guide" book. However I am >> little confused. In the book, the author extends UDAF class and implements >> init, iterate, terminatePartial, merge and terminate function. However >> looking at the hive docs ( >> http://hive.apache.org/docs/r0.11.0/api/org/apache/hadoop/hive/ql/exec/UDAF.html), >> it seems I need to implement init, aggregate, evaluatePartial, >> aggregatePartial and evaluate function. Please let me know what are the >> write functions to implement. >> >> Ritesh >> > > > > -- > Lefty >
