On 9/26/10 8:46 AM, "Christian Decker" <decker.christ...@gmail.com> wrote:
> It's been some while since I started using Cassandra in combination with > Pig, but I still haven't figured out the best way to work with the data. I > wrote some Index Readers based on the format that the contributed > CassandraStorage introduced (a tuple of the key and a databag which in turn > holds key-value tuples for the columns), but my Pig scripts by using this > method my scripts are riddled with $-signs: > > >> C1 = order rows by $1.$4.$1; > > > which continually break down as soon as I add some more columns to my CF. I > was working on a converter that takes the above mentioned format and > converted it to a Map<String, Object> but to no avail since when trying to > work on it, I bump my head against these: > > java.lang.ClassCastException: java.util.HashMap cannot be cast to >> org.apache.pig.data.Tuple > > > as soon as I make this: > > crows = FOREACH rows GENERATE CassandraConvert($0,$1) > > scrows = FOREACH crows GENERATE $0.uid; Does CassandraConvert return Map<String,Object> ? In that case your pig statement should be - scrows = FOREACH crows GENERATE $0#'uid'; -Thejas
