if (colType == null)
throw new SemanticException("column type not found");
ColumnStatsDesc cStatsDesc = new ColumnStatsDesc(tbl.getTableName(),
Arrays.asList(colName), Arrays.asList(colType), partSpec == null);
ColumnStatsUpdateTask cStatsUpdateTask = (ColumnStatsUpdateTask) TaskFactory
.get(new ColumnStatsUpdateWork(cStatsDesc, partName, mapProp), conf);
rootTasks.add(cStatsUpdateTask);
}