mergeFilesDesc.getOutputDir());
mergeWork.setListBucketingCtx(mergeFilesDesc.getLbCtx());
mergeWork.resolveConcatenateMerge(db.getConf());
mergeWork.setMapperCannotSpanPartns(true);
DriverContext driverCxt = new DriverContext();
BlockMergeTask taskExec = new BlockMergeTask();
taskExec.initialize(db.getConf(), null, driverCxt);
taskExec.setWork(mergeWork);
taskExec.setQueryPlan(this.getQueryPlan());
int ret = taskExec.execute(driverCxt);
return ret;
}