Thanks for the guidance Dmitry. That gives me a picture where to start from :)
On Tue, Nov 24, 2009 at 3:47 AM, Dmitriy Ryaboy <[email protected]> wrote: > Hi Dhaval, > What do you mean by "a custom group function"? To create a function that > turns a tuple or a part of a tuple into a key you want to group by, you can > use a regular EvalFunc. To create a custom aggregation function that > performs some calculation on the result of grouping, you still write a > regular EvalFunc, except it must work on a bag. You can implement the > Algebraic interface to make it run faster: > http://hadoop.apache.org/pig/docs/r0.5.0/udf.html . > > If you are working with the version in trunk, there is another interface > you > can implement for further efficiency gains, if it is applicable to your use > case: http://wiki.apache.org/pig/PigAccumulatorSpec > > <http://wiki.apache.org/pig/PigAccumulatorSpec>-Dmitriy > > On Tue, Nov 24, 2009 at 3:56 AM, dhaval deshpande < > [email protected]> wrote: > > > Hi, > > i wanted to create a custom group function in pig. I was not sure > > where to start from. I check some documentation online but couldnt figure > > out. I also checked on wiki and it says I need to extend a abstract class > > GroupFunc. and when i try to do that it says GroupFunc class doesnt not > > exist. Please help me where do I start from. > > > > Thanks, > > Dhaval. > > >
