thanks for all yours answers. Michael G.
2012/6/3 Jagat <[email protected]> > Hi > > Alan has already given you background of append in Hadoop. > > Another suggestion to merge two files , you can also look at Pig Union > > http://pig.apache.org/docs/r0.10.0/basic.html#union > > UNION operator to merge the contents of two or more relations > The simple workflow can be > > load A > load B > Store union of A and B > > Have a look at how Pig Union works > On Sun, Jun 3, 2012 at 8:28 AM, Alan Gates <[email protected]> wrote: > > > MapReduce (and hence Pig) does not support file append. This is because > > in MapReduce tasks may be run multiple times in the case of failure or > due > > to speculative execution. This would result in duplicate appends. Also, > > if the job fails, it would not be able to remove the appended data. > > > > As far as updating your data, what kind of updates do you want to do? > > Stores like HBase (which can be accessed from Pig) support updates. But > > whether this is a good fit depends on your use case. > > > > Alan. > > > > On Jun 1, 2012, at 11:54 AM, Michael G. wrote: > > > > > Hi all > > > I'm new in pig and in hadoop . > > > Can you tell me how I can : > > > 1. append to existing file on HDFS with pig > > > 2. update file with pig, if it could be passible. > > > > > > 10x. > > > > > > -- > > > -- Michael G. -- > > > > > -- -- Michael G. --
