@Override
  public void updateCreationMetadata(String catName, String dbname, String tablename, CreationMetadata cm)
      throws MetaException {
    boolean success = false;
    try {
      openTransaction();
      catName = normalizeIdentifier(catName);
      dbname = normalizeIdentifier(dbname);
      tablename = normalizeIdentifier(tablename);
      // Update creation metadata
      MCreationMetadata newMcm = convertToMCreationMetadata(cm);
      MCreationMetadata mcm = getCreationMetadata(catName, dbname, tablename);
      mcm.setTables(newMcm.getTables());
      mcm.setMaterializationTime(newMcm.getMaterializationTime());
      mcm.setTxnList(newMcm.getTxnList());
      // commit the changes
      success = commitTransaction();
      cm.setMaterializationTime(newMcm.getMaterializationTime());
    } finally {
      rollbackAndCleanup(success, null);
    }
  }
Verifies that the stats JSON string is unchanged for alter table (txn stats).
@return Error message with the details of the change, or null if the value has not changed.
standalone-metastore/metastore-server/src/main/java/org/apache/hadoop/hive/metastore/ObjectStore.java