The programme is introduced by Frank Lovis who points out the special nature of computer Tiles stressing their dynamic aspects. Don Yeates of the British Oxygen Company then illustrates how files c...an be organised on tape and disc and shows a simple model of sequential updating. Frank Lovis follows this by placing it in the context of one of the main course case studies - the children's immunisation programme at Kingston-Upon-Hull.
|Module code and title:
|PM951, Computing and computers
|First transmission date:
|Restrictions on use:
|+ Show more...
|F. B.(Frank B.) Lovis; Donald Yeates
|Children's immunisation programme; Computer files; Dynamic aspects; Kingston-Upon-Hull; Sequential ipdating
|The programme is introduced by Frank Lovis who points out the special nature of computer files stressing their dynamic aspects. He mentions the three basic file handling operations of inserting, deleting and updating material and shows a standard printed dictionary as an example of an inflexible file. Don Yeates discusses the organisation of files on magnetic tape. He points out the disadvantages of accessing sequential files, and the need to concentrate information in blocks as long as possible to reduce the percentage of tape wasted by inter-block gaps. He uses a model to demonstrate this. Yeates explains the concept of disc storage, illustrating his argument with diagrams. A film animation shows how disc files are read. Yeates mentions some factors involved in deciding on sequential or random organisation for a particular file. He explains how random organisation on disc works, and the need for a key index. Using film animation, Yeates shows how indexed sequential filing on disc works. Using a model, he demonstrates the operations involved in updating a stock holding file, showing the four different logical processes required; updating, deleting, adding new and passing over existing records. To end the programme Frank Lovis relates Yeates discussion to a practical example: the Hull immunisation records case study. First he shows, on a chart, the operations required by the system. He then uses a second model to show how this is carried out by the computer program. In conclusion, he stresses that this example covers only the updating of a sequential file on tape, and poses a final question: what is the inadequacy of the simplified results program he has described?
|Master spool number:
|Available to public: