About splitting support for bzip2, I checked on the JIRA list and found
HADOOP-7386 marked as "Won't fix"; I also found some work done in
branch-0.21(also in trunk), say HADOOP-4012 and MAPREDUCE-830, but not
integrated/migrated into branch-1, so I guess we don't support contatenated
bzip2 in branch-1, correct? If so, is there any special reason? Many thanks!