Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!cwjcc!gatech!psuvax1!psuvm!uh2
From: UH2@PSUVM.BITNET (Lee Sailer)
Newsgroups: comp.databases
Subject: Re: Referential Integrity in commercial DBMS's?
Message-ID: <89259.111659UH2@PSUVM.BITNET>
Date: 16 Sep 89 15:16:59 GMT
References: <5030@merlin.usc.edu>
Organization: Penn State University
Lines: 14

I'm not sure what level of Referential Integrity Unify guarantees, but
I do know that Rbase does.  You can specify a rule such as

ManagerID not NULL and ManagerID = EmployeeID in Employee

(tho' the syntax is a little different) which will reject any record
with a null ManagerID or for whom the ManagerID is not a valid employee.

The main problem with RBase is that all it does at that point is barf.
There is no BEGIN TRANSACTION-END-COMMIT-ABORT capability built in.
You have to fake it by creating your own local tables, and only integrating
them into the real tables after all has checked out.

                                                    lee