Yup, everything you can do in pig is doable in normal Hadoop. When you say you want to compare the keys, you're sort of doing an outer join. That's why I thought pig may make your life a bit easier,
Good luck. Aaron On 17/01/2011, at 1:07 PM, Jun Young Kim <juneng...@gmail.com> wrote: > Hi aron. > > I think that if the pig is able to support to map it, the same job could be > represented in java code itself. > > I believe that we can call a map function by loading a file and cassandra at > the same time. > > Ps) I dont need to join from them. I just wanna compare each keys which are > read from them. > > Thanks. > > 2011. 1. 17. 오전 5:56에 "Aaron Morton" <aa...@thelastpickle.com>님이 작성: > > The Pig readers are just the same as any other data source so you should > > be able to mix and match them as you please > > > > Tthe sample pig script in contrib/pig/example-script.pig specifies the to > > use the CassandraStorage source when loading data > > > > rows = LOAD 'cassandra://Keyspace1/Standard1' USING CassandraStorage(); > > > > The LOAD command in Pig Latin supports a USING keyword to identify the data > > source type > > http://pig.apache.org/docs/r0.8.0/piglatin_ref2.html#Load%2FStore+Functions > > > > I'm less familiar with Hadoop, but it should be possible. AFAIK though it's > > going to be easier to do a join between data sources with Pig. > > > > Hope that helps. > > Aaron > > > > > > > > On 15 Jan, 2011,at 06:00 PM, 김준영 <juneng...@gmail.com> wrote: > > > > hi, > > > > cassandra supports hadoop to map & reduce from cassandra. > > > > now I am digging to find out a way to map from a file and cassandra > > together. > > > > I mean if both of them are files in my disk, it is possible by using splits. > > > > but, in this kind of a situtation, which way is posssible? > > > > for example. > > > > in a cassandra) > > key1| value1 | value2 > > key2| value3 | value4 > > key3| value5 | value6 > > > > in a file) > > key1| value1 | value2 > > key2| value7 | value4 > > key3| value7 | value6 > > > > > > the size of both are very hugh. > > I want to get a result from diff from both of them. > > > > which keys are deleted? > > which values are changed? > > > > thanks.
