Sounds good! Please give some examples :) I just got back from some holidays and will start posting some more stuff shortly
Cheers James. On 2010-07-21, at 7:22 PM, Jeff Zhang wrote: > Cool, James. I am very interested to contribute to this. > I think group by, join and order by can been added to the examples. > > > On Thu, Jul 22, 2010 at 4:59 AM, James Seigel <ja...@tynt.com> wrote: > >> Oh yeah, it would help if I put the url: >> >> http://github.com/seigel/MRPatterns >> >> James >> >> On 2010-07-21, at 2:55 PM, James Seigel wrote: >> >>> Here is a skeleton project I stuffed up on github (feel free to offer >> other suggestions/alternatives). There is a wiki, a place to commit code, a >> place to fork around, etc.. >>> >>> Over the next couple of days I’ll try and put up some sample samples for >> people to poke around with. Feel free to attack the wiki, contribute code, >> etc... >>> >>> If anyone can derive some cool pseudo code to write map reduce type >> algorithms that’d be great. >>> >>> Cheers >>> James. >>> >>> >>> On 2010-07-21, at 10:51 AM, James Seigel wrote: >>> >>>> Jeff, I agree that cascading looks cool and might/should have a place in >> everyone’s tool box, however at some corps it takes a while to get those >> kinds of changes in place and therefore they might have to hand craft some >> java code before moving (if they ever can) to a different technology. >>>> >>>> I will get something up and going and post a link back for whomever is >> interested. >>>> >>>> To answer Himanshu’s question, I am thinking something like this (with >> some code): >>>> >>>> Hadoop M/R Patterns, and ones that match Pig Structures >>>> >>>> 1. COUNT: [Mapper] Spit out one key and the value of 1. [Combiner] Same >> as reducer. [Reducer] count = count + next.value. [Emit] Single result. >>>> 2. FREQ COUNT: [Mapper] Item, 1. [Combiner] Same as reducer. [Reducer] >> count = count + next.value. [Emit] list of Key, count >>>> 3. UNIQUE: [Mapper] Item, One. [Combiner] None. [Reducer + Emit] spit >> out list of keys and no value. >>>> >>>> I think adding a description of why the technique works would be helpful >> for people learning as well. I see some questions from people not >> understanding what happens to the data between mappers and reducers, or what >> data they will see when it gets to the reducer...etc... >>>> >>>> Cheers >>>> James. >>>> >>> >> >> > > > -- > Best Regards > > Jeff Zhang
