Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!cs.utexas.edu!uunet!virtech!cpcahil
From: cpcahil@virtech.UUCP (Conor P. Cahill)
Newsgroups: comp.databases
Subject: Re: Referential Integrity in commercial DBMS's?
Message-ID: <1172@virtech.UUCP>
Date: 17 Sep 89 00:35:14 GMT
References: <5030@merlin.usc.edu> <89259.111659UH2@PSUVM.BITNET>
Organization: Virtual Technologies Inc
Lines: 28

In article <89259.111659UH2@PSUVM.BITNET>, UH2@PSUVM.BITNET (Lee Sailer) writes:
> 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

You can specify the same thing in unify.  

> (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.

Again, same with unify.

> 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.

This is similar to the way unify behaved in versions 3.2 and 4.0, but with
unify 2000 you have the full begin, commit and/or abort transaction 
capability.


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