(e.g. when moving data between a DCOracleStorage and a FileStorage),
especially the method copyTransactionsFrom, as in:

  import ZODB.FileStorage, DCOracle, DCOracleStorage

  # Copy data.fs to oracle
  DCOracleStorage.Full(
    lambda : DCOracle.Connect('user/pw@sid')
    ).copyTransactionsFrom(
      ZODB.FileStorage.FileStorage('Data.fs', read_only=1)
    )