books

P R O L O G - - d a t a b a s e book leaves a few stones unturned Prolo9 and databases: implementa- tions and new directions P M D Gray and R J Lucas (eds) Ellis Horwood, Chichester, UK (1988) 356 pp £39.95 hardback

The book provides, at a broad level of detail, descriptions of the imple- mentation of SQL using PROLOG, the use of PROLOG to access multiple potentially different databases, and PROLOG in the context of deductive databases and its use for recursive query processing. There is some dis- cussion of the implications so far as implementation is concerned, and new applications and interfaces are also dealt with.

The SQL implementation and the approach to heterogeneous database environments is impressively com- pact. This is understandable given the expressive power of PROLOG. As

usual, there remains the question of providing a complete and efficient implementation. The discussion of implementation implications is limited to the description of a specia- lized file structure and general dis-

cussions of some implementations. The sections that deal with interfac- ing issues describe among other things a spreadsheet-like system for interfacing to a database and the use of PROLOG in building natural lan- guage-based database interfaces.

The papers appear to be accurate and well written (I only found one major ' typo' , page 105 'mand ' in- stead of 'manf'), but I disagree with some components of the stated au- dience. Specifically, I do not think that the average database specialist or industrial user will find much ma- terial of any immediate use in the book.

I would also voice something of a general disappointment so far as the content of the book is concerned.

Following Backus, PROLOO can be seen as one approach to the libera- tion of programming from the Von Neumann style. It provides an approach to the statement of an al- gorithm or a process in such a way that the statement itself has useful formal characteristics and is suscept- ible to analysis and, presumably, therefore to criticism and improve-

ment. The application of PROLOG in a data management environment where it is used only to solve purely programming problems is relatively uninteresting. The data management world does have its counterpart of the lack of useful formal characteris- tics quoted by Backus in the context of programming languages. This counterpart is to be found in the lack of clarity and direction so far as data modelling and database design is concerned.

There is no attempt to address these issues; the nearest approach to them is to be found in the papers that deal with interfacing issues. In these papers the fact that the problems are not confronted makes the proposed solutions strikingly weak. This is a straightforward corollary of the fact that the characteristics of a database interface are closely tied to the struc- ture of the database itself. If the structure of the database is not clearly defined and understood, the interface will inevitably be weak.

J P T H O M P S O N Mission Viego, CA, USA

College textbook on information processing is well written Introduction to computers and infor- mation processin9 L Long Prentice Hall, Englewood Cliffs, N J, USA (1988) 426pp £16.95 softback

This text does not say specifically at whom it is aimed; however, since it provides two distinct prefaces, one for the student and one for the in- structor, it is clear that it is intended to be used as a college textbook. Having read the book, it would seem, from the remarks below, that it would be suitable for those students doing courses in computing and data processing, or, to give it its new title, information processing, which serve as subsidiary courses to a different

degree discipline. It would be suit- able also for use as an introductory text in some single subject honours courses in computing but may well be avoided by many university lec- turers because it mentions BASIC. Finally, it would be appropriate for those studying O-Level computing.

The author has divided the book into five major sections, all entertain- ingly written, with one or more coloured pictures on most pages. The five sections cover the history of computing (two chapters), hardware (four), software (two), management information systems (two), and opportunity and challenge (four). At the end of a chapter, the student finds some review exercises and some self-

test questions: the former need some- what lengthy answers in contrast to the latter, which are answered simply with true or false.

The next item of note is that the author is American, and while on the one hand that will give him access to a vast source of material, on the other hand it means that the spell- ings (e.g., color and (dollar) cheques) are all American. Another con- sequence of this is that there are no pictures of non-American computers but almost every American computer manufacturer can boast at least one picture.

I found the chapter on the history of computing very interesting. Scant mention is made of Blaise Pascal and

396 information and software technology

books little more on Charles Babbage. The author does acknowledge Babbage's Difference engine and produces a coloured picture, courtesy of the New York Public Library Picture Collection. (Does he know the original is in the Science Museum in London?) Mention is made of Herman Hollerith, and of the found- ing of IBM in 1924, although no mention is made of Thomas J Watson. Alas, too, no mention is made of any of the early pioneering work carried out at Cambridge and Manchester, England; this means that there is no mention of the world's first computer program to run in erasable store (what today is called RAM). There is no mention too of the work done by Zuse in Germany. I suppose the author would probably say that something had to be omitted to keep it within

14 pages. The rest of the book is very up to

date. It mentions the IBM PS/2 and laser discs and printers and has a picture of a beautiful oriental rug design being printed on a colour printer. While complimenting the author on this colour photograph of the process of producing a silicon chip, I would take away the mark because the photos are all from dif- ferent manufacturers: it becomes much less easy to follow the process. On the software side, mention is made of c, PASCAL, FORTRAN, and ADA.

I liked the widespread applications of computers, covering among others, their uses in hospitals, air- lines, the legal profession, space- craft, and the stock-exchange (cf big- bang).

For those who have a dislike of

BASIC, it should be said that the chapter on BASIC can be ignored without detriment to the rest of the book, as can the chapter on number systems (10 pages). The book ends with a good glossary (eight page- s). In summary therefore, an inter- esting book and one that can fulfil the role outlined for it above. There are many associated aids produced for the teachers (instructor's re- source manual, study guide, and lab manual, together with video tapes) which are available for those with enthusiasm. The price of the book (£t6.95) is clearly fixed by the large number of coloured photographs: I hope that UK students will be able to afford this price. I would recom- mend the book to libraries as well.

B RICHARDS UMIST, Manchester, UK

Solid project management text lacks on new insights Stuctured computer project managemen t W H Roetzheim Prentice Hall, Englewood Cliffs, N J, USA (1988) 285 pp £37.45 hardback

This book is aimed squarely at the professional information systems project manager (who may be dis- guised under such other titles as sys- tems manager, product manager, project leader, senior systems analyst, etc.) and sets out to provide a structured, step-by-step approach to project management, to replace the art of project management by the science of project management. The presentation is from the view of a third-party software house and makes frequent reference to the legal contract with the customer. This po- tentially narrows the target audience, but many of the ideas are applicable to and maybe adapted by the 'in house' project manager.

Despite the 'structured' in the title and the 'advanced' in the heading of

part 3, the text contains few new insights into the traditional project management techniques covered in many cheaper publications; also, re- cent alternative approaches, such as prototyping or incremental develop- ment, are merely referenced indir- ectly or not addressed at all. The traditional techniques are reinforced with plenty of examples, but too much emphasis is given to structured analysis and structured program- ming, which I have never considered as part of project management per se (the book may be more accurately classified as being a software engin- eering text). Also, I have serious mis- givings about any 1988 publication that references flowcharting as any- thing other than an historical aberra- tion.

I found the style of the book rather patronising and a majority of the diagrams unnecessary and, therefore, annoying. The author acknowledges the use of Diagraph in producing the diagrams, which too often appear to demonstrate the software rather than

to illustrate the point of the text. The book also publicizes the author's project management software, but did not have the opportunity to re- view this tool.

When addressing project manage- ment, the book largely meets its ob- jectives but at £37.45 is rather over- priced and will certainly not replace Burrill and Ellsworth 1, the definitive text on traditional project manage- ment, or Gilb 2, for more modern approaches, in my bookcase.

R E F E R E N C E S

1 Burriil, C W and Elisworth, L W Modern project management: Joundations for quality and pro- ductivity Burrill-Ellsworth Asso- ciates (1980)

2 Gilb, T Principles of software man- agement Addison-Wesley, Read- ing, MA, USA (1988)

D WILSON University of Technology, Sydney,

Australia

vol 31 no 7 september 1989 39"7