Re: RM and abstract syntax trees

From: David BL <davidbl_at_iinet.net.au>
Date: Fri, 09 Nov 2007 16:34:37 -0800
Message-ID: <1194654877.790046.216350@s15g2000prm.googlegroups.com>

On Nov 10, 5:29 am, Marshall <marshall.spi..._at_gmail.com> wrote:

> The issue is that pointers need referencing and dereferencing
> operators which are not part of the relational algebra. Pointers
> have an associated address space. Pointers are volatile and
> anchored to a specific run of a specific program on a specific
> machine, whereas relational ids are durable. Pointers are
> physical and ids are logical.

You appear to draw conclusions from your assumption that the RDB is durable whereas the machine process is not. What happens if you delete the RDB? To what extent is a bank account identifier meaningful without the associated DB?

What about pointers between objects in a POS (Persistent Object Store)? Are you saying they aren't really pointers because the address space is durable?

I would rather say that the pointer concept is orthogonal to volatile versus durable concerns. Received on Fri Nov 09 2007 - 18:34:37 CST