# Package net.corda.node.services.persistence

- Class Summary
  Class | Description
  --- | ---
  DBCheckpointStorage | Simple checkpoint key value storage in DB using the underlying JDBCHashMap and transactional context of the call sites.
  DBTransactionMappingStorage | Database storage of a txhash -> state machine id mapping.
  DBTransactionStorage |
  DataVending |
  InMemoryStateMachineRecordedTransactionMappingStorage | This is a temporary in-memory storage of a state machine id -> txhash mapping
  NodeAttachmentService | Stores attachments in the specified local directory, which must exist. Doesn't allow new attachments to be uploaded.
  StorageServiceImpl |