Re: Pizza Example
Date: Sun, 18 Apr 2004 11:19:30 GMT
Anthony W. Youngman wrote:
> In message <h2jdc.64877$%m6.4324481_at_phobos.telenet-ops.be>, Jan Hidders
> <jan.hidders_at_REMOVETHIS.pandora.be> writes
>> Dawn M. Wolthuis wrote: >> >>> So, if "the Pizza has Mozzarella and Parmesan cheese" is stored as: >>> Pizza Mozzarella >>> Parmesan >>> in a single, uh, record, then if the ordering is unwittingly useful, we >>> didn't harm that ordering. >> >> >> Indeed, but you did make certain query-optimizations impossible. Never >> mind that what you are advocating is basically sloppy data modelling. >>
> What optimisations?
Certain join reorderings. Joins on lists are not commutative.
> Okay, Pick forces more stuff into the conscious
> design of the db programmer, but an index on cheese and I don't see what
> queries can't be optimised.
That doesn't surprise me.
- Jan Hiddesr