It’s a bit of a blog frenzy today!<\/p>\n
On the 3rd November last year, immediately after the UKOUG conference, there was a seminar in Edinburgh to discuss temporal databases<\/a>. (Mogens blogged about it here<\/a> and I’d mentioned some of Rob Squire’s work here<\/a>.) I had planned to go initially but was unable to get the time off work. However, Peter Robson<\/a> attended as one of the instigators. Peter’s a friend who I’ve been encouraging to blog. Here’s his response to that idea<\/p>\n “I am someone wary of ‘the blog’, as a contributory activity to data overload, and therefore a medium, if I were to write one, that I would exercise so infrequently that everyone would forget I even had one! So I am grateful to you for inviting a contribution from myself!”<\/p>\n I asked Peter if he would contribute a guest blog giving his perspective on the seminar because I have a few regular readers now who might be interested. So, it’s over to Peter …. and as I’m aware how contentious a subject this could be, I’ll be ducking down immediately after posting 😉<\/p>\n “I recently attended a couple of lectures covering aspects of data warehouse, which prompted the very real question \ufffd is there any future for the data warehouse approach?<\/p>\n The first lecture was an all-day seminar from Chris Date on temporal database. This seminar was closely based on the book – Temporal Data & the Relational Model – by himself, Hugh Darwen and Nikos Lorentzos. It is the temporal component of database which becomes particularly significant in the data warehouse context. Chris took the relational model as his starting point, and basically introduced extensions to it which would in no way compromise the existing model. Consideration of intervals, pack and unpack functions, and the necessity for a final normal form (Sixth) were all aspects of his presentation. The point to note (without understanding the details of his presentation) was that the subject matter was complex, and required very careful attention on the part of the audience to follow his line of argument. Chris provided twelve archetypal queries that any competent temporal database must be able to solve to be worthy of the name. (It will not have escaped the attentive reader that the original tests for relational completeness presented by Ted Codd numbered also twelve …)<\/p>\n The final part of the day was given over to a presentation by Rob Squire of Oracle, who presented some of the research work that he has been doing on temporal database. He addressed exactly the same problems which Chris had explored, but with significant differences. His demonstration used the existing relational model (as implemented by Oracle) without ANY extensions. His demonstrations were all in standard SQL*Plus. Although he was somewhat reticent concerning the exact technology (there are IPR issues involved here), he used a view approach to provide what he described as a ‘temporal normal form’ over the existing data model. His demonstration showed how his approach enabled him to solve several of the twelve key queries that Chris Date had presented. He is confident of solving all of them. (Please note this work does NOT comprise an Oracle product.)<\/p>\n A couple of weeks later I attended a data warehouse meeting organised by DAMA (The Data Management Association), which gave great opportunity to discuss matters relating to data warehouse issues. What was significant here was the answer provided by one of the data warehouse gurus when the following question was put to him: <\/p>\n “How much longer can the data warehouse continue to exist as a separate database concept in the face of <\/p>\n a) increasing hardware performance <\/p>\n b) cheaper storage <\/p>\n c) the appearance of powerful functions within SQL*Plus?” <\/em><\/p>\n (Note? … Tom Kyte once said at a UKOUG conference presentation that he didn’t think there was anything he could not do in SQL*Plus which previously required a 3GL, given the appearance of the functions now present in SQL). <\/p>\n The answer from the data warehouse guru was basically … “Probably not much longer.”<\/p>\n Couple that with the progress made by Rob Squire without the use of functions or extension, and I would suggest that the days of the data warehouse may indeed be limited. The unanswered question of course is whether the solution proposed by Chris Date is required to handle temporal data, or whether that proposed by Rob Squire is sufficient? It is my intention to get Rob to demonstrate the solution of the twelve queries using a test database, but loaded with very large quantities of data. We need to understand just how Rob’s solution conforms to, and varies from that proposed by Chris Date. I am also working on a plan to get Chris to present his solution using the TransRelational Model – but once again there are IPR issues here.<\/p>\n Watch this space!”<\/p><\/blockquote>\n My thanks to Peter for the contribution. If nothing else, you’ve certainly raised the standard of written English 😉<\/p>\n","protected":false},"excerpt":{"rendered":"