Re: Databases as objects

RA is great, but it proves only structural (relational) correctness. If
there's an algebra for network databases then it could prove structural
(network) correctness as well. I think both are good things.

In addition to structural correctness we can test for semantic
correctness. In banking systems one way to do that is to compare all
the debit and credit accounts to make sure they net $0.


Why wouldn't relational algebra be able to do that? A simple select
sum() would solve the problem.

In that case, at least, sum() is how we do it.

Sum is a standard aggregate function availible in relational algebra.
(It is also possible to define custom functions, if needed, and use
them in RA expressions.) Why can RA not be used for evaluating semantic
correctness?

Fredrik Bertilsson
http://frebe.php0h.com

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Relevant Pages

  • Re: Databases as objects
    ... there's an algebra for network databases then it could prove structural ... In addition to structural correctness we can test for semantic ... Why wouldn't relational algebra be able to do that? ...
    (comp.object)
  • Re: Databases as objects
    ... there's an algebra for network databases then it could prove structural ... In addition to structural correctness we can test for semantic ... In that case, at least, sum() is how we do it. ...
    (comp.object)