public void decreaseTableAttributeMemory(final String table, final long num) {
    tableAttributeMemory.computeIfPresent(table, (tableName, size) -> size - num);
  }
This class is used to record statistics within the SchemaRegion in Memory mode.
iotdb-core/datanode/src/main/java/org/apache/iotdb/db/schemaengine/rescon/MemSchemaRegionStatistics.java