Most companies simply don't have the data volume to make Hadoop worthwhile. You can process tens of TB in an RDBMS on a beefy machine cheaper than a Hadoop clus

Most companies simply don't have the data volume to make Hadoop worthwhile. You can process tens of TB in an RDBMS on a beefy machine cheaper than a Hadoop cluster. Hadoop is slow, but on huge data volume the overheads are dwarfed by the parallelism gained. Most companies don't have huge volume though. For example recently I saw someone propose using Hadoop for a sub-TB dataset...