VISIT REPORT L. Burnard

ICL Euston

IDMS DMUG EUFSG(79) 4th Meeting

18 May 79

Presentations given included: a man from MOD explaining a little of how they currently support their requirement for a query language suitable for use by Admirals, Flight Commanders and such like when playing toy soldiers.

The current system apparently uses lots of discrete files, some of which (we were told with a straight face) were designed 'as long ago as 1812') It seemed that the similarity of their query language to English was possible largely because of the limited type of queries the system had to support. They were thinking of expanding from queries about the positions of friendly/unfriendly vessels to queries about something called 'signals' but did not seem to anticipate any problems. As far as their account of it went, there seemed to be very little syntactic component in their processor. M R Jackson (ICL) spoke on FOCUS a highly impressive American software-house package which provides an interface between just about everything and everything else. Since it interfaces to IMS and to conventional files as well as IDMS, the data model used is limited to hierarchies, which makes for some contortions when handling IDMS databases. Its range of facilities (graphics, stats etc) was staggering, as was its price. Richard Barker (ICL) gave a short outline of the new facilities in ICL's own Data Display at the next release (DD200) (some of which look very nice) to see whether the group considered DD a suitable base for a query language. No firm conclusion was reached: despite its nice new facilities, DD is probably best used as a DML programmers aids.

After initial false starts, discussion centred on the type of conceptual view the EUF should support. It was not clear whether a separate view was required for the interface between the conceptual view/s and the IDMS structures: whether we were discussing an hourglass (pace Tim Bourne) or a pyramid (pace everyone else). Favourite candidate for the pinnacle (or the waist) is currently the Entity Model already used by DDS, to no-one's particular surprise; I shall certainly do my best to push the case of the relational view, preferably binary, at the next meeting when current work will be summarised/ discussed. Meanwhile ICL is still committed to marketing RDBMS 'at some stage' but not (it now appears) as a product integrated with other Data Management products.