@Override
  public String getDatabaseName() {
    return databaseName;
  }
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