Re: Zero-length structures and pointer comparisons

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Article #1117

#1117

From: Fergus James HENDERSON
Date: Mon, 21 Dec 1992 11:01

22 lines
1497 bytes

jbn@lulea.trab.se (Johan Bengtsson) writes:

>Markku Sakkinen (sakkinen@jyu.fi) wrote:
>: BTW, actually total order is
>: a simple thing within an OODB _because_ the identity of each object
>: is assured not to change.
>
>It would impose severe restrictions on how the virtual address space
>could be used though.  The OODBMS may end up in a situation where
>it can't get a persistent object into memory, not because it has used up
>all virtual memory addresses, but because all unused virtual memory
>adresses would violate the total ordering property.

I thought that the idea was that for OODBMSs, you DON'T compare virtual
addresses for pointers to persistent objects, instead you compare the object
ids. Maybe someone could explain the problems in a little more detail?

-- 
Fergus Henderson             fjh@munta.cs.mu.OZ.AU      
This .signature virus is a self-referential statement that is true - but 
you will only be able to consistently believe it if you copy it to your own
.signature file!

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Path: arc1-ca.pugleaf.net!sparky!uunet!munnari.oz.au!cs.mu.OZ.AU!munta.cs.mu.OZ.AU!fjh
From: fjh@munta.cs.mu.OZ.AU (Fergus James HENDERSON)
Subject: Re: Zero-length structures and pointer comparisons
Message-ID: <9235622.25587@mulga.cs.mu.OZ.AU>
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Organization: Computer Science, University of Melbourne, Australia
References: <1992Dec8.143504.5590@jyu.fi> <5343@holden.lulea.trab.se>
Date: Mon, 21 Dec 1992 11:01:23 GMT
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