The data library is a room often adjacent to the computer center that provides safe storage for the off- line data files, such as magnetic tapes and removable disk packs. A data librarian who is responsible for the receipt, storage, retrieval, and custody of data files controls access to the library. The librarian issues tapes to computer operators and takes custody of files when processing is completed. The move to real- time processing and direct access files (discussed in Chapter 2) has reduced or eliminated the role of the data librarian in most organizations.