Search results

Items of information that have been stored in a computer normally need to be accessed via their contents. In principle this is always possible by doing an exhaustive scan of the entire file of information, but to achieve the access efficiently we use some sort of organizing principle, a file organization or file structure, to reduce the amount anning. Typically the items retrieved are a response to a request which fully or partially specifies their contents. Often the file organization requires pre‐processing of the body of information so that a secondary body of information (an index or directory) may be created which in some sense reveals the contents of the file. So, ultimately file structures are time saving devices, where we pay for the time saved by extra storage. They enable us quickly to find items of information by completely or partially specifying their contents.

This study guide should start with an explanation of what I mean by filing systems. Whether one is referring to the filing of records on a shelf or the filing order of papers within a record, both are filing systems and both are organised differently. To cover filing systems in a comprehensive way, therefore, we not only have to discuss both of these systems but also the numbering and organisation of records or papers that allow them to be filed and retrieved. Drawing on examples from the health service, this study guide will cover the following topics: • numbering systems • filing within a record • methods of filing • filing of a record within a filing system • tracing records within the filing system It is important to emphasise the importance of a well organised and maintained filing systems without which many businesses and organisations could not function efficiently.

Two types of linear on‐line search have been implemented on a data base of 100,000 INSPEC records, and compared with an inverted search program on the same file. It was found that the linear search which does a character‐by‐character scan of the whole file was too slow to be useful as an on‐line search, but that the second linear search, which uses a linear file of keys to select records for full scanning, was useable on‐line. An algorithm suitable for the on‐line searching of the linear file of keys is presented with run time nearly independent of the number of terms in the search query. Neither of the linear searches can compete with an inverted search in terms of user convenience, but they do not require as complex file‐maintenance software, they use less processing time to build indexes, and they have lower storage requirements than inverted files.

This is the third of a series of tabular presentations of data for operational computerised loans or circulation systems in specified countries. It follows the pattern established by the previous tabulations by grouping information about the systems covered under the series of descriptive headings that was developed as one of the first tasks of the then Circulation Working Party of the Aslib Computer Applications Group.

This paper describes the development, through three versions, of a computer‐based subject‐index production scheme designed as a complement to a system producing MARC‐based catalogues for a library cooperative. The scheme provides an individual subject index to each member of the cooperative and a union subject index to the whole, or any part, of the group. The major advantages of the scheme are simplicity and attention to practical detail. The disadvantages are an eighty‐character limitation on record length and complete dependance on manually produced records. The scheme is designed to handle records carrying Dewey classification numbers.

The design and development of a computer‐based information system requires an understanding of the operating system of the computer. This knowledge helps in efficient file design for optimal utilisation of disk space which results in increased system efficiency. This paper describes an Indian multi‐tasking/multi‐programming operating system called WDOS, especially its data‐structure and how an online, multi‐user bibliographic information storage and retrieval system has been developed under it utilising the knowledge of its operating system. A set of functional specifications drawn in consultation with users has guided the system development work. The system has been validated and successfully implemented. It has been found to be efficient in terms of response time and this may be attributed to its file design.

This paper describes the development of a fault‐tolerant database processor (DBP) system to replace OCLC's conventional file system, which not only improves overall system reliability and database availability, but also facilitates the operation and management of a large and rapidly growing online database. This database processor became operational on 16 October 1978, an achievement that represents a significant advance in the operation of information storage and retrieval systems.

From modest beginning a decade ago and foresight in the planning stages has grown an inexpensive, efficient and effective on‐line retrieval system. This paper traces the development and mechanization which resulted in a viable bibliographic information system, describes its present capabilities, and indicates directions for future growth.

Discusses one application of a commercially available computer software package suitable for scientific and technical information storage and retrieval. Source documents, mode of input, indexing technique and thesaurus control are described. The various forms of output which are generated and the services available to users are explained. These services include retrospective searching of the database, and provision of printed indexes and personalised current awareness.