Lawhon, Alan C Contractor/Morgan Research
alan.lawhon at us.army.mil
Fri Sep 30 09:43:31 CDT 2005
Arthur, Charlotte: Several years ago I recall buying (and trying to comprehend) relational database guru Chris Date's "classic" book (it's more like a tome ...) "An Introduction to Database Systems". (Chris Date's main claim to fame is as a protégé of the late Dr. E.F. "Ted" Codd - the "father" of the relational database model.) Date worked with Dr. Codd in the early 1970's at IBM. He is now a full time consultant and writer - mostly of articles dealing with various topics related to database design. Chris Date is a relational "purist" (some might say a zealot) in arguing that a database system (or a vendor implementation of a database system) cannot be considered truly "relational" if it violates any of Codd's "Ten Rules" of relational database design. (Without "naming names," Chris Date excoriates various vendor implementations of the relational model in his book. He accuses these vendors of committing various "unforgivable sins" against the relational model. Chris Date implies (or in some cases flat out states) that these "sins" [of implementation] will lead to nothing but trouble when commercial systems are designed and built using these "flawed" implementations. (I'm doing a lot of paraphrasing of Chris Date's words and writing here, but I think I have the "general drift" of Date's criticisms just about right.) I think part of the "problem" (from the vendors perspective) may be that creating a [truly] "relational" database system that passes muster with Chris Date is probably very difficult - not to mention very costly. (After investing literally BILLIONS of dollars in research and development, a vendor may come up with an implementation that meets the requirements of six or seven of the ten rules - and ignores (or "violates") the other three rules. Chris Date focuses in on the three (or four) rules that have been violated - and declares the whole implementation "fatally flawed". I would have to go back and re-read "An Introduction to Database Systems," but I have a feeling that the introduction of "Multi-choice combos" is the kind of thing that will drive Chris Date up the wall. Alan C. Lawhon -----Original Message----- From: accessd-bounces at databaseadvisors.com [mailto:accessd-bounces at databaseadvisors.com] On Behalf Of Arthur Fuller Sent: Friday, September 30, 2005 8:40 AM To: 'Access Developers discussion and problem solving' Subject: Re: [AccessD] The future of Access, .NET and SQL You can add MySQL to your list of offending databases. MySQL offends in two ways, actually, but I will leave that as an exercise for the interested reader. -----Original Message----- From: accessd-bounces at databaseadvisors.com [mailto:accessd-bounces at databaseadvisors.com] On Behalf Of Charlotte Foust Sent: September 29, 2005 11:05 AM To: Access Developers discussion and problem solving Subject: Re: [AccessD] The future of Access, .NET and SQL I haven't *seen* it. The stated concept gives me shivers because of "databases" like Approach and FileMaker that have allowed multiple choices stored in a single field. Charlotte -----Original Message----- From: Arthur Fuller [mailto:artful at rogers.com] Sent: Wednesday, September 28, 2005 8:05 PM To: 'Access Developers discussion and problem solving' Subject: Re: [AccessD] The future of Access, .NET and SQL Multi-choice combos <> relational constraints! Case in point: I want to add N children to a parent, whose DetailType is selected from a multi-choice combo.... i.e. add a Hotel, a CarRental, a ConcertTicket, an AirportShuttle. The UI lets me do this as quickly as possible, and background code takes care of the Parent-Child relationships. I see no problem here. What are you seeing? -----Original Message----- From: accessd-bounces at databaseadvisors.com [mailto:accessd-bounces at databaseadvisors.com] On Behalf Of Charlotte Foust Sent: September 28, 2005 11:22 AM To: Access Developers discussion and problem solving Subject: Re: [AccessD] The future of Access, .NET and SQL >> Multi-choice combo box (M-M joins) That's the one I find scary. Does that mean they're abandoning relational design? Charlotte -----Original Message----- From: Gustav Brock [mailto:Gustav at cactus.dk] Sent: Wednesday, September 28, 2005 6:32 AM To: accessd at databaseadvisors.com Subject: Re: [AccessD] The future of Access, .NET and SQL Hi all OK, found something in the slides at the links from Jim. Does anyone know if "Append only" is fixed or optional? <snip> ACE - Access Data Engine - Engine based on Jet code-base and installed with Office, 100% backwards compatible with Jet - Connects to external data sources - Foundation for richer support of complex data - Multi-choice combo box (M-M joins) - Attachments - Append only - Read and write Excel "12" file formats - SharePoint ISAM enhancements - OM changes to DAO and ACE OLEDB provider (ADO) </snip> I guess OM here means Object Model. Further: <snip> New ACCDB file format - Can be emailed and stored in SharePoint document libraries - Default for all new database - Supports complex data features - Multiple value lookups - Attachments - Append only - SharePoint list offline - Office file encryption not Jet encoding </snip> Also this summary: <snip> - Microsoft is committed to Access as a developer platform - SharePoint Services integration allows developers to build new types of collaborative applications - Developers can build and deploy tracking templates </snip> Note that an Outlook code example in the presentation uses DAO, so this seems not to be "dead" at all. /gustav >>> Gustav at cactus.dk 27-09-2005 21:03 >>> Hi Susan and Martin Thanks! Just wondering what this new engine should be about ... -- AccessD mailing list AccessD at databaseadvisors.com http://databaseadvisors.com/mailman/listinfo/accessd Website: http://www.databaseadvisors.com -- AccessD mailing list AccessD at databaseadvisors.com http://databaseadvisors.com/mailman/listinfo/accessd Website: http://www.databaseadvisors.com -- AccessD mailing list AccessD at databaseadvisors.com http://databaseadvisors.com/mailman/listinfo/accessd Website: http://www.databaseadvisors.com -- AccessD mailing list AccessD at databaseadvisors.com http://databaseadvisors.com/mailman/listinfo/accessd Website: http://www.databaseadvisors.com -- AccessD mailing list AccessD at databaseadvisors.com http://databaseadvisors.com/mailman/listinfo/accessd Website: http://www.databaseadvisors.com