# Re: Guessing?

From: Brian Selzer <brian_at_selzer-software.com>
Date: Thu, 19 Jun 2008 21:35:43 -0400
Message-ID: <QPD6k.9141\$xZ.1710@nlpi070.nbdc.sbc.com>

"paul c" <toledobysea_at_ac.ooyah> wrote in message news:63z6k.38054\$gc5.18499_at_pd7urf2no...

```> Brian Selzer wrote:
>> "paul c" <toledobysea_at_ac.ooyah> wrote in message
>> news:etU_j.167881\$rd2.59570_at_pd7urf3no...
>>> Brian Selzer wrote:
```

>>>> news:483ac46d\$0\$4069\$9a566e8b_at_news.aliant.net...
```>>>>> paul c wrote:
> ...
>>>>> With POOD, any tuple satisfies the predicate of at most one relation
>>>>> in the dbms. Thus, with POOD, the dbms can calculate a unique relation
>>>>> to which to apply any insert, update or delete with the goal of
>>>>> avoiding anomalous behaviour.
>>>>>
```

>>>> This just does not make sense. Suppose that a Vendor can also be a
>>>> Customer since they're both Companies, and suppose that Company
>>>> 'Philco' usually supplies 'RG6 connectors,' but occasionally buys them.
>>>> So then if you have two relations,
```>>>>
```

>>>> VendorParts {Company, Part},
```>>>>
```

>>>> CustomerParts {Company, Part},
```>>>>
```

>>>> that enumerate the parts that a company supplies and the parts that a
```>>>>
```

>>>> the tuple, {Company:'Philco', Part:'RG6 connector'}, can obviously
>>>> appear in both relations, so I don't buy the notion 'any tuple
>>>> satisfies the predicate of at most one relation.'
>>>> ...
```>>>
>>> Isn't this a straw man too?  (arguing against POOD with an example that