Thanks guys, Sebastian
On 8/28/07, Bart Degryse <[EMAIL PROTECTED]> wrote: > > <quote>Im using Django as my Object relational Mapper so im pretty sure I > can not add a constraint such as ...</quote> > Then you should seriously consider changing your mapper. > > >>> "Sebastian Ritter" <[EMAIL PROTECTED]> 2007-08-28 16:37 >>> > Thanks for the information. > > Both tables would be exactly sames apart from the foreign key relation to > clients or services. I agree that it seems strange to have one column that > is always null. Im using Django as my Object relational Mapper so im pretty > sure I can not add a constraint such as : CHECK constraint where !(col1 > IS NULL and col2 IS NULL). > > Another factor ive been considering is that one of the fields in this > table(s) definition(s) is free flowing text which could potentially become > very large. Should I take this in to > consideration when deciding whether to split the tables? In terms of > searching speed that is. > > Kindest regards. > Sebastian > > On 8/28/07, Andrew Sullivan <[EMAIL PROTECTED]> wrote: > > > > On Tue, Aug 28, 2007 at 12:47:45PM +0100, Sebastian Ritter wrote: > > > > The update/message format is exactly the same for both. Should I > > make two > > > > different tables: > > > > > > one table with extra columns : is_client, client_id, service_id, > > where > > > > either client_id or service_id would be null depending on the > > is_client > > > > boolean? > > > > Is the rest of the data the same? If so, then one table is right. > > If not, then more than one table. In either case, I really hate the > > idea of two columns, one of which is always null. But if you're > > going to do that, make sure you add a CHECK constraint where !(col1 > > IS NULL and col2 IS NULL). > > > > A > > > > -- > > Andrew Sullivan | [EMAIL PROTECTED] > > I remember when computers were frustrating because they *did* exactly > > what > > you told them to. That actually seems sort of quaint now. > > --J.D. Baldwin > > > > ---------------------------(end of broadcast)--------------------------- > > TIP 3: Have you checked our extensive FAQ? > > > > http://www.postgresql.org/docs/faq > > > >
