Re: does a table always need a PK?
Date: 27 Aug 2003 03:50:40 -0700
Message-ID: <bcb8c360.0308270250.40de43a6_at_posting.google.com>
Hello,
"Heikki Tuuri" <Heikki.Tuuri_at_innodb.com> wrote in message news:<SiQ2b.467$4X.270_at_read3.inet.fi>...
> Yes. But a "DBMS" is a vague concept and I do not have time to define
> "Heikki Tuuri -DBMS".
>
Questions that spring to mind :
a) How can someone writing/supporting/selling/extending/whatever-InnoDB's-relationship-to-MySql-might-be
honestly say a DBMS is a vague concept ? Is that because MySql is only
very vaguely a DBMS ?
b) Taking a wild leap of faith and assuming that MySql *is* a DBMS for
the moment, wouldn't it have been wise to define "Heikki Tuuri -DBMS"
before starting ?
> > Does SQL provide perfect relational fidelity?
>
> Yes, if we define a relational database as an SQL database. Not in the sense
> of Codd-1970-relational.
>
If we define cats as dogs, a lion could win Crufts next year.
<snippage>
> Yes, lots of databases do. But MySQL/InnoDB is released under the GNU GPL
> license and it is fast. Transaction management in InnoDB is rather complete
> with next-key locking, multiversioning, and all 4 isolation levels defined
> by SQL-1992.
>
So, you too can have a DBMS-not-quite-workalike, but at least it's
free. And it's fast. Right up to the point where it all goes wrong,
when it gets expensive and slow to fix. Does the term "faster
disaster" occur to anyone else ?
<snippage>
> > Overall, do any other SQL dbms products provide greater relational
> fidelity
> > than your product?
>
> Many databases are more Codd-12-relational than MySQL/InnoDB.
>
Databases, or DBMSs ?
<snippage>
> > From the answers to the above questions, one should be able to judge the
> > competence, honesty and integrity of an SQL dbms vendor.
>
> Well, not really. Customers never ask the above questions. Honesty is better
> judged from answers to questions which matter to the customer.
>
D'oh ? So, to put it another way, a supplier could lie through its
teeth about whether it's sunny or raining, what the current share
price is, or indeed the price of cheese, but that doesn't matter
because share prices, the price of cheese and prevailing weather
conditions aren't that important to me ? What sort of relationship
(sorry) is founded on such a basis ?
- Tony