private List<Tuple> getAllPartitions(Schema outSchema) {
    List<TablePartitionProto> partitionList = masterContext.getCatalog().getAllPartitions();
    List<Tuple> tuples = new ArrayList<Tuple>(partitionList.size());
    List<Column> columns = outSchema.getRootColumns();
    Tuple aTuple;

    for (TablePartitionProto partition : partitionList) {
      aTuple = new VTuple(outSchema.size());

      for (int fieldId = 0; fieldId < columns.size(); fieldId++) {
        Column column = columns.get(fieldId);

        if ("partition_id".equalsIgnoreCase(column.getSimpleName())) {
          aTuple.put(fieldId, DatumFactory.createInt4(partition.getPartitionId()));
        } else if ("tid".equalsIgnoreCase(column.getSimpleName())) {
          aTuple.put(fieldId, DatumFactory.createInt4(partition.getTid()));
        } else if ("partition_name".equalsIgnoreCase(column.getSimpleName())) {
          if (partition.hasPartitionName()) {
            aTuple.put(fieldId, DatumFactory.createText(partition.getPartitionName()));
          } else {
            aTuple.put(fieldId, DatumFactory.createNullDatum());
          }
        } else if ("path".equalsIgnoreCase(column.getSimpleName())) {
          aTuple.put(fieldId, DatumFactory.createText(partition.getPath()));
        }
      }

      tuples.add(aTuple);
    }

    return tuples;
  }
  private List<Tuple> getAllTableOptions(Schema outSchema) {
    List<TableOptionProto> optionList = masterContext.getCatalog().getAllTableOptions();
    List<Tuple> tuples = new ArrayList<Tuple>(optionList.size());
    List<Column> columns = outSchema.getRootColumns();
    Tuple aTuple;

    for (TableOptionProto option : optionList) {
      aTuple = new VTuple(outSchema.size());

      for (int fieldId = 0; fieldId < columns.size(); fieldId++) {
        Column column = columns.get(fieldId);

        if ("tid".equalsIgnoreCase(column.getSimpleName())) {
          aTuple.put(fieldId, DatumFactory.createInt4(option.getTid()));
        } else if ("key_".equalsIgnoreCase(column.getSimpleName())) {
          aTuple.put(fieldId, DatumFactory.createText(option.getKeyval().getKey()));
        } else if ("value_".equalsIgnoreCase(column.getSimpleName())) {
          aTuple.put(fieldId, DatumFactory.createText(option.getKeyval().getValue()));
        }
      }

      tuples.add(aTuple);
    }

    return tuples;
  }
  private List<Tuple> getAllTableStats(Schema outSchema) {
    List<TableStatsProto> statList = masterContext.getCatalog().getAllTableStats();
    List<Tuple> tuples = new ArrayList<Tuple>(statList.size());
    List<Column> columns = outSchema.getRootColumns();
    Tuple aTuple;

    for (TableStatsProto stat : statList) {
      aTuple = new VTuple(outSchema.size());

      for (int fieldId = 0; fieldId < columns.size(); fieldId++) {
        Column column = columns.get(fieldId);

        if ("tid".equalsIgnoreCase(column.getSimpleName())) {
          aTuple.put(fieldId, DatumFactory.createInt4(stat.getTid()));
        } else if ("num_rows".equalsIgnoreCase(column.getSimpleName())) {
          aTuple.put(fieldId, DatumFactory.createInt8(stat.getNumRows()));
        } else if ("num_bytes".equalsIgnoreCase(column.getSimpleName())) {
          aTuple.put(fieldId, DatumFactory.createInt8(stat.getNumBytes()));
        }
      }

      tuples.add(aTuple);
    }

    return tuples;
  }
  private List<Tuple> getTables(Schema outSchema) {
    List<TableDescriptorProto> tables = masterContext.getCatalog().getAllTables();
    List<Tuple> tuples = new ArrayList<Tuple>(tables.size());
    List<Column> columns = outSchema.getRootColumns();
    Tuple aTuple;

    for (TableDescriptorProto table : tables) {
      aTuple = new VTuple(outSchema.size());

      for (int fieldId = 0; fieldId < columns.size(); fieldId++) {
        Column column = columns.get(fieldId);
        if ("tid".equalsIgnoreCase(column.getSimpleName())) {
          aTuple.put(fieldId, DatumFactory.createInt4(table.getTid()));
        } else if ("db_id".equalsIgnoreCase(column.getSimpleName())) {
          aTuple.put(fieldId, DatumFactory.createInt4(table.getDbId()));
        } else if ("table_name".equalsIgnoreCase(column.getSimpleName())) {
          aTuple.put(fieldId, DatumFactory.createText(table.getName()));
        } else if ("table_type".equalsIgnoreCase(column.getSimpleName())) {
          if (table.hasTableType()) {
            aTuple.put(fieldId, DatumFactory.createText(table.getTableType()));
          } else {
            aTuple.put(fieldId, DatumFactory.createNullDatum());
          }
        } else if ("path".equalsIgnoreCase(column.getSimpleName())) {
          aTuple.put(fieldId, DatumFactory.createText(table.getPath()));
        } else if ("store_type".equalsIgnoreCase(column.getSimpleName())) {
          aTuple.put(fieldId, DatumFactory.createText(table.getStoreType()));
        }
      }

      tuples.add(aTuple);
    }

    return tuples;
  }
  private List<Tuple> getDatabases(Schema outSchema) {
    List<DatabaseProto> databases = masterContext.getCatalog().getAllDatabases();
    List<Tuple> tuples = new ArrayList<Tuple>(databases.size());
    List<Column> columns = outSchema.getRootColumns();
    Tuple aTuple;

    for (DatabaseProto database : databases) {
      aTuple = new VTuple(outSchema.size());

      for (int fieldId = 0; fieldId < columns.size(); fieldId++) {
        Column column = columns.get(fieldId);
        if ("db_id".equalsIgnoreCase(column.getSimpleName())) {
          aTuple.put(fieldId, DatumFactory.createInt4(database.getId()));
        } else if ("db_name".equalsIgnoreCase(column.getSimpleName())) {
          aTuple.put(fieldId, DatumFactory.createText(database.getName()));
        } else if ("space_id".equalsIgnoreCase(column.getSimpleName())) {
          if (database.hasSpaceId()) {
            aTuple.put(fieldId, DatumFactory.createInt4(database.getSpaceId()));
          } else {
            aTuple.put(fieldId, DatumFactory.createNullDatum());
          }
        }
      }

      tuples.add(aTuple);
    }

    return tuples;
  }
  private List<Tuple> getTablespaces(Schema outSchema) {
    List<TablespaceProto> tablespaces = masterContext.getCatalog().getAllTablespaces();
    List<Tuple> tuples = new ArrayList<Tuple>(tablespaces.size());
    List<Column> columns = outSchema.getRootColumns();
    Tuple aTuple;

    for (TablespaceProto tablespace : tablespaces) {
      aTuple = new VTuple(outSchema.size());

      for (int fieldId = 0; fieldId < columns.size(); fieldId++) {
        Column column = columns.get(fieldId);
        if ("space_id".equalsIgnoreCase(column.getSimpleName())) {
          if (tablespace.hasId()) {
            aTuple.put(fieldId, DatumFactory.createInt4(tablespace.getId()));
          } else {
            aTuple.put(fieldId, DatumFactory.createNullDatum());
          }
        } else if ("space_name".equalsIgnoreCase(column.getSimpleName())) {
          aTuple.put(fieldId, DatumFactory.createText(tablespace.getSpaceName()));
        } else if ("space_handler".equalsIgnoreCase(column.getSimpleName())) {
          if (tablespace.hasHandler()) {
            aTuple.put(fieldId, DatumFactory.createText(tablespace.getHandler()));
          } else {
            aTuple.put(fieldId, DatumFactory.createNullDatum());
          }
        } else if ("space_uri".equalsIgnoreCase(column.getSimpleName())) {
          aTuple.put(fieldId, DatumFactory.createText(tablespace.getUri()));
        }
      }
      tuples.add(aTuple);
    }

    return tuples;
  }
  private Tuple getWorkerTuple(Schema outSchema, Worker aWorker) {
    List<Column> columns = outSchema.getRootColumns();
    Tuple aTuple = new VTuple(outSchema.size());
    WorkerResource aResource = aWorker.getResource();

    for (int fieldId = 0; fieldId < columns.size(); fieldId++) {
      Column column = columns.get(fieldId);

      if ("host".equalsIgnoreCase(column.getSimpleName())) {
        if (aWorker.getConnectionInfo() != null && aWorker.getConnectionInfo().getHost() != null) {
          aTuple.put(fieldId, DatumFactory.createText(aWorker.getConnectionInfo().getHost()));
        } else {
          aTuple.put(fieldId, DatumFactory.createNullDatum());
        }
      } else if ("port".equalsIgnoreCase(column.getSimpleName())) {
        if (aWorker.getConnectionInfo() != null) {
          aTuple.put(
              fieldId, DatumFactory.createInt4(aWorker.getConnectionInfo().getPeerRpcPort()));
        } else {
          aTuple.put(fieldId, DatumFactory.createNullDatum());
        }
      } else if ("type".equalsIgnoreCase(column.getSimpleName())) {
        aTuple.put(fieldId, DatumFactory.createText("Worker"));
      } else if ("status".equalsIgnoreCase(column.getSimpleName())) {
        aTuple.put(fieldId, DatumFactory.createText(aWorker.getState().toString()));
      } else if ("RUNNING".equalsIgnoreCase(aWorker.getState().toString())) {
        if ("total_cpu".equalsIgnoreCase(column.getSimpleName())) {
          aTuple.put(fieldId, DatumFactory.createInt4(aResource.getCpuCoreSlots()));
        } else if ("used_mem".equalsIgnoreCase(column.getSimpleName())) {
          aTuple.put(fieldId, DatumFactory.createInt8(aResource.getUsedMemoryMB() * 1048576l));
        } else if ("total_mem".equalsIgnoreCase(column.getSimpleName())) {
          aTuple.put(fieldId, DatumFactory.createInt8(aResource.getMemoryMB() * 1048576l));
        } else if ("free_heap".equalsIgnoreCase(column.getSimpleName())) {
          aTuple.put(fieldId, DatumFactory.createInt8(aResource.getFreeHeap()));
        } else if ("max_heap".equalsIgnoreCase(column.getSimpleName())) {
          aTuple.put(fieldId, DatumFactory.createInt8(aResource.getMaxHeap()));
        } else if ("used_diskslots".equalsIgnoreCase(column.getSimpleName())) {
          aTuple.put(fieldId, DatumFactory.createFloat4(aResource.getUsedDiskSlots()));
        } else if ("total_diskslots".equalsIgnoreCase(column.getSimpleName())) {
          aTuple.put(fieldId, DatumFactory.createFloat4(aResource.getDiskSlots()));
        } else if ("running_tasks".equalsIgnoreCase(column.getSimpleName())) {
          aTuple.put(fieldId, DatumFactory.createInt4(aResource.getNumRunningTasks()));
        } else if ("last_heartbeat_ts".equalsIgnoreCase(column.getSimpleName())) {
          if (aWorker.getLastHeartbeatTime() > 0) {
            aTuple.put(
                fieldId,
                DatumFactory.createTimestmpDatumWithJavaMillis(aWorker.getLastHeartbeatTime()));
          } else {
            aTuple.put(fieldId, DatumFactory.createNullDatum());
          }
        }
      } else {
        aTuple.put(fieldId, DatumFactory.createNullDatum());
      }
    }

    return aTuple;
  }
  private List<Tuple> getColumns(Schema outSchema) {
    List<ColumnProto> columnsList = masterContext.getCatalog().getAllColumns();
    List<Tuple> tuples = new ArrayList<Tuple>(columnsList.size());
    List<Column> columns = outSchema.getRootColumns();
    Tuple aTuple;
    int columnId = 1, prevtid = -1, tid = 0;

    for (ColumnProto column : columnsList) {
      aTuple = new VTuple(outSchema.size());

      tid = column.getTid();
      if (prevtid != tid) {
        columnId = 1;
        prevtid = tid;
      }

      for (int fieldId = 0; fieldId < columns.size(); fieldId++) {
        Column colObj = columns.get(fieldId);

        if ("tid".equalsIgnoreCase(colObj.getSimpleName())) {
          if (column.hasTid()) {
            aTuple.put(fieldId, DatumFactory.createInt4(tid));
          } else {
            aTuple.put(fieldId, DatumFactory.createNullDatum());
          }
        } else if ("column_name".equalsIgnoreCase(colObj.getSimpleName())) {
          aTuple.put(fieldId, DatumFactory.createText(column.getName()));
        } else if ("ordinal_position".equalsIgnoreCase(colObj.getSimpleName())) {
          aTuple.put(fieldId, DatumFactory.createInt4(columnId));
        } else if ("data_type".equalsIgnoreCase(colObj.getSimpleName())) {
          aTuple.put(fieldId, DatumFactory.createText(column.getDataType().getType().toString()));
        } else if ("type_length".equalsIgnoreCase(colObj.getSimpleName())) {
          DataType dataType = column.getDataType();
          if (dataType.hasLength()) {
            aTuple.put(fieldId, DatumFactory.createInt4(dataType.getLength()));
          } else {
            aTuple.put(fieldId, DatumFactory.createNullDatum());
          }
        }
      }

      columnId++;
      tuples.add(aTuple);
    }

    return tuples;
  }
  private List<Tuple> getIndexes(Schema outSchema) {
    List<IndexProto> indexList = masterContext.getCatalog().getAllIndexes();
    List<Tuple> tuples = new ArrayList<Tuple>(indexList.size());
    List<Column> columns = outSchema.getRootColumns();
    Tuple aTuple;

    for (IndexProto index : indexList) {
      aTuple = new VTuple(outSchema.size());

      for (int fieldId = 0; fieldId < columns.size(); fieldId++) {
        Column column = columns.get(fieldId);

        if ("db_id".equalsIgnoreCase(column.getSimpleName())) {
          aTuple.put(fieldId, DatumFactory.createInt4(index.getDbId()));
        } else if ("tid".equalsIgnoreCase(column.getSimpleName())) {
          aTuple.put(fieldId, DatumFactory.createInt4(index.getTId()));
        } else if ("index_name".equalsIgnoreCase(column.getSimpleName())) {
          aTuple.put(fieldId, DatumFactory.createText(index.getIndexName()));
        } else if ("column_name".equalsIgnoreCase(column.getSimpleName())) {
          aTuple.put(fieldId, DatumFactory.createText(index.getColumnName()));
        } else if ("data_type".equalsIgnoreCase(column.getSimpleName())) {
          aTuple.put(fieldId, DatumFactory.createText(index.getDataType()));
        } else if ("index_type".equalsIgnoreCase(column.getSimpleName())) {
          aTuple.put(fieldId, DatumFactory.createText(index.getIndexType()));
        } else if ("is_unique".equalsIgnoreCase(column.getSimpleName())) {
          aTuple.put(fieldId, DatumFactory.createBool(index.getIsUnique()));
        } else if ("is_clustered".equalsIgnoreCase(column.getSimpleName())) {
          aTuple.put(fieldId, DatumFactory.createBool(index.getIsClustered()));
        } else if ("is_ascending".equalsIgnoreCase(column.getSimpleName())) {
          aTuple.put(fieldId, DatumFactory.createBool(index.getIsAscending()));
        }
      }

      tuples.add(aTuple);
    }

    return tuples;
  }
  private List<Tuple> getSessionInfo(Schema outSchema) {
    List<Tuple> outputs = Lists.newArrayList();
    Tuple eachVariable;

    try {
      for (Map.Entry<String, String> var :
          masterContext.getSessionManager().getAllVariables(sessionId).entrySet()) {
        eachVariable = new VTuple(outSchema.size());
        eachVariable.put(0, DatumFactory.createText(var.getKey()));
        eachVariable.put(1, DatumFactory.createText(var.getValue()));

        outputs.add(eachVariable);
      }
    } catch (InvalidSessionException e) {
      LOG.error(e);
    }

    return outputs;
  }