Re: Mixing OO and DB
Date: Sat, 22 Mar 2008 15:28:46 +0100
Message-ID: <15cap5z1o8l2u$.s5t12tsztg38.dlg_at_40tude.net>
On Fri, 21 Mar 2008 22:42:44 -0700 (PDT), frebe wrote:
>> The claim that the application can't do translations is
>> incorrect, on its face. SQL isn't going to return DAGs, or even
>> queues, stacks, or maps.
>
> A DAG can obviously be represented as a set of tuples.
LOL. For that matter, a DAG can be represented by a natural number. This by no means imply that ALU were operating DAGs, or that the ADD instruction would return DAGs. You could certainly represent DAG by used paper cups...
> The same
> applies to queues, stacks or maps, even though I can't really see why
> you need a low-level data structure like a map, when relations are
> availible.
Because an algebraic structure is not just a set. Isomorphism of elements does not make algebraic structures same. Is it so difficult to grasp?
P.S. To the list of problems I put before you to solve:
(Message ID: 16zwfmkrguxvp.xiq5rgz36sbc.dlg_at_40tude.net)
- Let G be a DAG. Compute G* (transitive closure).
-- Regards, Dmitry A. Kazakov http://www.dmitry-kazakov.deReceived on Sat Mar 22 2008 - 15:28:46 CET