Regardless of what mapper features you layer on top of a model, you still have to have the model describing all tables around...
Sure, by tendency having more tables then are needed is waste, and statistically the more there are the more likely you're running down the wrong lane. However, here are datamodels which are huge and complex for a reason, and even if they aren't, you still gotta deal with them because it's your job. And when you walk up to a manager and tell him that the last 20 years of db-design by his engineer team are crap, and that you'd like to throw it away mostly they get that funny look (you know which one). Yadda yadda yadda blah blah blah, final conclusion: Dealing with many tables is an inevitable task you'll encounter when working as an application developer for db-driven applications for a company. The fact that you have to deal with reality even if you don't like it doesn't go away by singing "lalala I can't hear you". Quoting Michael Bayer <[EMAIL PROTECTED]>: > regardless of if you have a DB with 250 or 1000 tables. is it then > appropriate to have 1000 separate classes ? shouldnt the concepts of > some of those tables be rolled up into coarser-grained domain > objects ? whats the point of using an ORM and a domain model really > if youre just going to represent each table completely literally > within the application, when the tables are that exploded ? might as > well just store lists of dictionaries. heres the real question I > should have asked: how many *concepts* does your application have ? > > I have only seen one database schema that had several hundred tables > before. the guy basically represented every single element of a > large and complicated DTD as a separate table, i.e. <taga> was one > table, <tagb> was another, etc. To him, that was "proper third > normal form" and any other method of representing XML was "wrong". > There was an ERWIN printout of the whole schema on the wall. it took > about 130 sheets of paper to print and took up about 16 feet of > wallspace, floor to ceiling. he had the relationships between every > table wired up in such a way that looked like the Matrix. nobody on > earth could ever understand or work with such a schema, and if > someone ever wanted to change the DTD, the entire application would > have to be rewritten. > > you cant tell me thats the proper way to do something. and even if > it was, you dont represent an XML document with a different class for > each XML tag, you use a DOM tree, which uses about half a dozen classes. > > > On May 7, 2006, at 2:44 AM, Florian Boesch wrote: > > > I used to do work for financial institutes, and usually there's > > always a > > handfull of old db driven projects around that get dragged on > > forever, they'd > > have hundreds if not thousands of tables. And if you walk into > > their office > > rooms, they'd use huge DB diagrams of their app as wallpaper (must > > be a nerd > > thing). Usually they'd have one or multiple people work on a table > > complex that > > somewhere bordered with other table complexes. > > > > Quoting Jonathan Vanasco <[EMAIL PROTECTED]>: > >> Florian is right. its a strict 3nf and a giant data model that is as > >> highly relational as it is gigantic. I tried to split it out into 4 > >> sep. databases, but needed to join too much of the data to do it any > >> other way than fully integrated. > >> > >> considering simple bulletin board apps that you can download as foss > >> apps are around ~30 tables, i don't think even 400 tables is too big > >> for something structured to be a serious enterprise application. > >> > >> On May 6, 2006, at 3:57 PM, Florian Boesch wrote: > >> > >>> C'mon you can be nicer then that. Sure 234 tables is much, but not > >>> that much for > >>> a big data model and a strict 3rd normalform design. I mean, I > >>> consider myself > >>> running a fairly simple datamodel, and what I do is fairly gruft > >>> free as it's > >>> fresh, and it has easely accumulated 50 tables. 234 doesn't seem > >>> like a stretch > >>> for me at all. > >>> > >>> Quoting Michael Bayer <[EMAIL PROTECTED]>: > >>> > >>>> id ask why you have 234 tables in the first place..... > >> > >> > >> > >> ------------------------------------------------------- > >> Using Tomcat but need to do more? Need to support web services, > >> security? > >> Get stuff done quickly with pre-integrated technology to make your > >> job easier > >> Download IBM WebSphere Application Server v.1.0.1 based on Apache > >> Geronimo > >> http://sel.as-us.falkag.net/sel? > >> cmd=lnk&kid=120709&bid=263057&dat=121642 > >> _______________________________________________ > >> Sqlalchemy-users mailing list > >> Sqlalchemy-users@lists.sourceforge.net > >> https://lists.sourceforge.net/lists/listinfo/sqlalchemy-users > >> > >> > > > > > > > > > > ------------------------------------------------------- > > Using Tomcat but need to do more? Need to support web services, > > security? > > Get stuff done quickly with pre-integrated technology to make your > > job easier > > Download IBM WebSphere Application Server v.1.0.1 based on Apache > > Geronimo > > http://sel.as-us.falkag.net/sel? > > cmd=lnk&kid=120709&bid=263057&dat=121642 > > _______________________________________________ > > Sqlalchemy-users mailing list > > Sqlalchemy-users@lists.sourceforge.net > > https://lists.sourceforge.net/lists/listinfo/sqlalchemy-users > > > > ------------------------------------------------------- > Using Tomcat but need to do more? Need to support web services, security? > Get stuff done quickly with pre-integrated technology to make your job easier > Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo > http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642 > _______________________________________________ > Sqlalchemy-users mailing list > Sqlalchemy-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/sqlalchemy-users > > ------------------------------------------------------- Using Tomcat but need to do more? Need to support web services, security? Get stuff done quickly with pre-integrated technology to make your job easier Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642 _______________________________________________ Sqlalchemy-users mailing list Sqlalchemy-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/sqlalchemy-users
