public String dbName() {
    return dbName;
  }
ColumnStatsUpdateWork implementation. ColumnStatsUpdateWork will persist the
colStats into metastore. Work corresponds to statement like ALTER TABLE
src_stat UPDATE STATISTICS for column key SET
('numDVs'='1111','avgColLen'='1.111'); ALTER TABLE src_stat_part
PARTITION(partitionId=100) UPDATE STATISTICS for column value SET
('maxColLen'='4444','avgColLen'='44.4');
ql/src/java/org/apache/hadoop/hive/ql/plan/ColumnStatsUpdateWork.java