@Override
  public List<String> getAllTokenIdentifiers() {
    LOG.debug("Begin executing getAllTokenIdentifiers");
    boolean committed = false;
    Query query = null;
    List<String> tokenIdents = new ArrayList<>();

    try {
      openTransaction();
      query = pm.newQuery(MDelegationToken.class);
      List<MDelegationToken> tokens = (List<MDelegationToken>) query.execute();
      pm.retrieveAll(tokens);
      committed = commitTransaction();

      for (MDelegationToken token : tokens) {
        tokenIdents.add(token.getTokenIdentifier());
      }
      return tokenIdents;
    } finally {
      LOG.debug("Done executing getAllTokenIdentifers with status : {}", committed);
      rollbackAndCleanup(committed, query);
    }
  }
Get partition's column stats

@return Map of column name and its stats
standalone-metastore/metastore-server/src/main/java/org/apache/hadoop/hive/metastore/ObjectStore.java