Have you renamed any tables used in the foreign keys (or dumped and restored with different names or some missing tables). Under 7.0.2 and earlier there is a problem with postgres crashing if a constraint trigger has bad values (due to renames or incomplete restores). This should be fixed for 7.1 with a message that it's unable to find the tablename. I believe that if you look through the archives (I forget which list though), you will find a patch for 7.0.2 that will turn the crash into an exception message with more information. Stephan Szabo [EMAIL PROTECTED] On Tue, 10 Oct 2000, lt wrote: > Hi, > I am using Postgresql 7.0.2, and have used some foreign key in my database, but I >get some error like "the backend ended the connection" where I am trying to insert or >delete a row to the master table(Delete cascade and update cascade). Of course, this >error is no use to find the reason. So I am forced to forget foreign keys. >