Re: does a table always need a PK?

After a long battle with technology,alfredo_at_ncs.es (Alfredo Novoa), an earthling, wrote:
> "Heikki Tuuri" <Heikki.Tuuri_at_innodb.com> wrote in message news:<FgK3b.436$st4.97_at_read3.inet.fi>...
>
>> Yes, the above definition is exact and mathematical, because it describes a
>> mathematical relation. It does not describe an 'RDBMS'. You cannot find a
>> formal specification of Codd's rules below from it.
>>
>> http://www.cis.ohio-state.edu/~sgomori/570/coddsrules.html
>
> Codd's rules are outdated. If you want a description of what an RDBMS
> is, I recomend you The Third Manifesto.
>
> BTW, does anybody knows if Date and Darwen are considering to drop
> transactions in the next revision?

Drop them? Or "drop them into the book"; they only made limited comment about them in the last revision. (Which doesn't imply that transactions are irrelevant, just that they weren't relevant to the points they were trying to make about relational databases.)

-- 
let name="aa454" and tld="freenet.carleton.ca" in name ^ "_at_" ^ tld;;
http://www3.sympatico.ca/cbbrowne/linuxxian.html
The  average woman would rather   have beauty than  brains because the
average man can see better than he can think.