@Override
  protected boolean isCacheEnabled() {
    return MetastoreConf.getBoolVar(conf,
            MetastoreConf.ConfVars.COMPACTOR_INITIATOR_TABLECACHE_ON);
  }
A class to initiate compactions.  This will run in a separate thread.
It's critical that there exactly 1 of these in a given warehouse.
ql/src/java/org/apache/hadoop/hive/ql/txn/compactor/Initiator.java