Tom, I have another instance of a possible function being used as a check constraint: a function that makes sure there is one row, and only one row in a table.
At table creation, and the creation of the constraint, there are no rows in the table. So, even if the constraint is a valid one to have, it will fail. We use check constraint functions in a few places, and they work just fine for us (minus the case of trying to restore the database from a pg_dump archive). Is it impossible to treat check constraints similar to other constraints and make them deferrable, specifically in the restoration from a pg_dump archive? Is there a specific reason check constraints are handled differently from other constraints? Jonathan Scott On Thu, 26 Feb 2004 08:54:59 -0500 Tom Lane <[EMAIL PROTECTED]> wrote: > Jonathan Scott <[EMAIL PROTECTED]> writes: > > The functions and tables create just fine, but when it gets to the > > COPY part of the sql script, it tries to load tables in what really is > > the wrong order. The check constraint is making sure there is a "plan" > > before there is a "contract", yet pg_dump is trying to load the > > contract table before there is anything in the plan table. > > Shouldn't you be using a foreign key for that? > > I don't see any reasonable way that pg_dump can be expected to > understand that a check constraint expresses a relationship between two > tables. The semantics of check constraints aren't right for it anyway. > > All else being equal, I think the tables will be loaded in OID order, > so a possible workaround is to create the plan table first. But an > FK seems like a better answer. > > regards, tom lane > > ---------------------------(end of broadcast)--------------------------- > TIP 8: explain analyze is your friend > -- Jonathan Scott, Programmer, Vanten K.K. [EMAIL PROTECTED] Tel: 03-5919-0266 http://www.vanten.com Fax: 03-5919-0267 ---------------------------(end of broadcast)--------------------------- TIP 1: subscribe and unsubscribe commands go to [EMAIL PROTECTED]
