VISIT REPORT

Jesus College, Cambridge

13-14 July 81

British National Conference on Databases

This was the first national conference on databases ever held. It was jointly organised by the BCS, Aberdeen University, Middlesex Polytechnic and Cambridge University, with money from IBM, and drew an unexpectedly large attendance of nearly 150, with equal numbers of delegates from both industry and academia. The standard of presentations,(with one or two exceptions) and of discussion was unusually high

for such encounters and I was able to continue discussions with some

delegates I had previously met in Cardiff at the rather less high-powered gathering I attended there last week. Another unusual feature of the conference was that all the papers given had been submitted in full in advance, and copies of the proceedings were thus made available before they occurred. (My copy is available for consultation).

Of the 11 papers presented, Deen gives a very useful summary of the state of the art in database research, at least as viewed from Aberdeen - which is probably a pretty good place to view it from; Zahran (LSE) proposes some less than revolutionary methods of extending the capability of Data Dictionary systems; Brown et al (id) give another glimmer of the long-awaited pot of gold which is ICL's RADS - an automatic program generator driven by the Data Dictionary. (I rather enjoyed this because I've never seen Jackson-structures actually being used for anything, but the computer scientists in the audience seemed rather restless. ) Gray (Aberdeen) continued his promotion of ASTRID, concentrating here on the GROUP-BY operator with which he claims to have completed the relational algebra. This was quite impressive, and it is probable that he will be coming to Oxford to test it on some of our databases in the near future. Tagg (independent consultant) gave a rather dull precis of the BCS's even duller report on query languages - dull because it leaves out all recent developments. Longstaff et al (Open U) described

their teaching system which translates queries from relational calculus back

into a restricted set of English or other natural language so that the user may check to see whether he has asked what he intended to ask, and also to teach by example the more obscure niceties of the calculus. Crowe et, al (Thames Poly) describe a similarly motivated system of infinitely less sophistication. Gray (Cambridge) outlines some of the problems of dealing with imprecise or unknown values in a database, using three valued logic, and lattice theory ; Clauert et al (Cambridge) describe their implementation of a CODD database distributed across several mini computers (This was amazingly complicated like most Cambridge procedures but apparently quite effective). Ho (Hong Kong)'s account of optimal search sequence, i.e. an algorithm for determining how different file organisations should be ranked when evaluating a query which will use several files was both inscrutable and, when understood, redundant. Finally Martin (Liverpool) presented the results of comparing one dead DBMS (Robot), one still born (RDBMS) , one adolescent (RAPPORT) and one real one (IDMS). Chief result was that Rapport queries wenre easier to write than Cobol DML programs …. varied immensely, with IDMS usually coming out on top.