private Date readDateValue(String dateStr) {
    // try either yyyy-mm-dd, or integer representing days since epoch
    try {
      DateWritableV2 writableVal = new DateWritableV2(org.apache.hadoop.hive.common.type.Date.valueOf(dateStr));
      return new Date(writableVal.getDays());
    } catch (IllegalArgumentException err) {
      // Fallback to integer parsing
      LOG.debug("Reading date value as days since epoch: {}", dateStr);
      return new Date(Long.parseLong(dateStr));
    }
  }
ColumnStatsUpdateTask implementation. For example, ALTER TABLE src_stat
UPDATE STATISTICS for column key SET ('numDVs'='1111','avgColLen'='1.111');
For another example, 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/exec/ColumnStatsUpdateTask.java