Re: Sql to Relational Algebra

"Bob Badour" <bbadour_at_golden.net> writes:

>> The pros and cons of SQL vs. quel are strictly in terms of human factors
>of
>> expressing queries.

>With all due respect, you are ignoring the fact that Quel is a less
>redundant language and how this impacts performance optimization.

which just means that the optimizer is a bit harder to implement in SQL. Note that many (though surely not all) of the redundant features in SQL were created to extend the power of SQL beyond relational calculus (and thus beyond QUEL). SQL optimizers today handle correlated nested queries that can be unwrapped into joins just fine, for example. I don't find SQL particularly intuitive, though.

Cheers,

joseph Received on Mon Sep 22 2003 - 06:36:41 CEST