Re: Demo: Modelling Cost of Travel Paths Between Towns

neo55592_at_hotmail.com (Neo) wrote in message news:<4b45d3ad.0411151728.739fd3ea_at_posting.google.com>...
> > UPDATE your_table
> > SET age = age + 1
> > WHERE name = 'john'
> > AND age IS NOT NULL
>
> You are not actually suggesting a solution with NULLs, are you?
>
> On page 571, 6th Ed of "An Intro to Db Systems", CJ Date states "NULLs
> and 3VL are a mistake and have no place in a clean formal system like
> the relational model".

I'm reading this from comp.databases, NOT comp.databases.theory

If you want to discuss theory, can you please provide references to the theory behind Xdb2? Peer-reviewed research would be most appropriate. Otherwise, I'll

1. continue to discuss this in terms of DBMS products, Xdb2 versus RDBMS based products like ORACLE
2. remove the c.d.theory crosspost in my replies after this one.

It is important to agree on whether we are discussing  FORMAL SYSTEMS or REAL PRODUCTS.

Neo, if you really want to discuss theory only, then I suggest you keep your discussion in the theory group. If you are trying to sell product, then I suggest you stay here in the generic group, and demonstrate features comparisons rather than theory. Whether 3VL is useful for a RDBM is irrelevant to comparing RDBMS to non-RDBMS like Xdb2.

  Ed Received on Mon Nov 22 2004 - 20:10:25 CET