public static DataNodeDevicePathCache getInstance() {
    return DataNodeDevicePathCache.DataNodeDevicePathCacheHolder.INSTANCE;
  }
This cache is for reducing duplicated DeviceId PartialPath initialization in write process.
iotdb-core/datanode/src/main/java/org/apache/iotdb/db/queryengine/plan/analyze/cache/schema/DataNodeDevicePathCache.java