Concepts
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have been clustered as clustered files
...Some of the work that has been largely ignored in this chapter,but which is nevertheless of importance when considering the implementation of a file structure,is concerned directly with the physical organisation of a storage device in terms of block sizes,etc
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| 67 |
packing the nodes of the tree on the disk given the access characteristics of the disk
...The work on data bases has been very much concerned with a concept called data independence
...There is a school of thought that says that says that applications in library automation and information retrieval should follow this path as well [6,7]...Nevertheless,it is worth taking seriously the trend away from user knowledge of file structures,a trend that has been stimulated considerably by attempts to construct a theory of data [8,9],which has become known as the relational model
...A second approach is the hierarchical approach
...The third approach is the network approach associated with the proposals by the Data Base Task Group of CODASYL
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The lesson that is to be learnt is that should new research get underway it will be very important to have a suitable data base ready
...Information retrieval systems are likely to play an every increasing part in the community
...One major recent development is that computers and data bases are becoming linked into A study recommending the provision of such an experimental test bed has recently been completed,see Sparck Jones and van Rijsbergen,Information retrieval test collections,Journal of Documentation,32,59 75 1976
...networks
...By extending the user population to include the non specialist,it is likely that an IR system will be expected to provide not just a citation,but a display of the text,or part of it,and perhaps answer simple questions about the retrieved documents
...To bring all this about the document retrieval system will have to be interfaced and integrated with data retrieval systems,to give access to facts related to those in the documents
...Another example can be found in the context of computer aided instruction,where it is clearly a good idea to give a student access to a document retrieval system which will provide him with further reading on a topic of his immediate interest
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