private void initDiskSelector() {
    switch (ILoadDiskSelector.LoadDiskSelectorType.fromValue(config.getLoadDiskSelectStrategy())) {
      case INHERIT_SYSTEM_MULTI_DISKS_SELECT_STRATEGY:
        ordinaryLoadDiskSelector = new InheritSystemMultiDisksStrategySelector();
        break;
      case MIN_IO_FIRST:
      default:
        ordinaryLoadDiskSelector = new MinIOSelector();
    }

    switch (ILoadDiskSelector.LoadDiskSelectorType.fromValue(
        config.getLoadDiskSelectStrategyForIoTV2AndPipe())) {
      case MIN_IO_FIRST:
        pipeAndIoTV2LoadDiskSelector = new MinIOSelector();
        break;
      case INHERIT_SYSTEM_MULTI_DISKS_SELECT_STRATEGY:
        pipeAndIoTV2LoadDiskSelector = new InheritSystemMultiDisksStrategySelector();
        break;
      case INHERIT_LOAD:
      default:
        pipeAndIoTV2LoadDiskSelector = ordinaryLoadDiskSelector;
    }
  }
Construct a database processor.

@param systemDir system dir path
@param dataRegionId data region id e.g. 1
@param fileFlushPolicy file flush policy
@param databaseName database name e.g. root.sg1
iotdb-core/datanode/src/main/java/org/apache/iotdb/db/storageengine/dataregion/DataRegion.java