Re: data management
From: paul c <toledobythesea_at_oohay.ac>
Date: Tue, 06 Jun 2006 01:49:36 GMT
Message-ID: <Qa5hg.243202$P01.19605_at_pd7tw3no>
> the
> a
> choosing a
>
> I think you're changing the subject. I suggested that supporting searches
> was a reason (perhaps THE reason) for building a database. You seem to be
> addressing the reason for building a DBMS. It isn't the same.
>
> BTW, enabling searches to find something is one way of supporting searches.
> In fact, searches that don't find anything can only be said to be productive
> if the fact that they didn't find anything carries some element of
> unexpectedness.
>
> This could bring us back to the curious incident of the dog in the night.
>
>
Date: Tue, 06 Jun 2006 01:49:36 GMT
Message-ID: <Qa5hg.243202$P01.19605_at_pd7tw3no>
David Cressey wrote:
> "mAsterdam" <mAsterdam_at_vrijdag.org> wrote in message
> news:44845403$0$31639$e4fe514c_at_news.xs4all.nl...
>> * changed subject line * >> x wrote: >>> David Cressey wrote: >>>> mAsterdam wrote: >>>>> Patrick May wrote: >>>>> >>>>>> I did not find him backing up his claims regarding Mr. Martin's >>>>>> "foolishness". Can you or can you not point out a specific example of >>>>>> him doing so? >>>>>> Robert Martin ha escrito: >>>>>> >>>>>>>> Ridiculous. OO and RDB coexist very nicely together. >>>>>>>> I've never heard anyone suggest >>>>>>>> that searches aren't needed. >>>>>> Relational databases have nothing to do with searches. >>>>>> This shows profound ignorance about data management theory. >>>> I disagree with both points. >>>> The need to support searches is one reason for building a database in
> the
>>>> first place. Perhaps the foremost reason. >>> I would say relational databases are more >>> about "finding" than about "searching" :-) >> > >>>> The way relational databases support searches is one reason for choosing
> a
>>>> relational database over some other kind. The same comment can be made >>>> regarding SQL databases. >>> The way relational databases support "finding" is one reason for
> choosing a
>>> database over a file system. :-) >> The need to support searching/finding is a reason >> for building fast access mechanisms, using indexes >> (isam, vsam, ...) or otherwise. >> >> DBMS's use these access mechanisms and provide an >> easy-to-use interface to them. Anybody who has a >> DBMS can simply use these as features. >> The ease this brings may give valid economical reasons >> to use a DBMS just to take care of searching. >>
>
> I think you're changing the subject. I suggested that supporting searches
> was a reason (perhaps THE reason) for building a database. You seem to be
> addressing the reason for building a DBMS. It isn't the same.
>
> BTW, enabling searches to find something is one way of supporting searches.
> In fact, searches that don't find anything can only be said to be productive
> if the fact that they didn't find anything carries some element of
> unexpectedness.
>
> This could bring us back to the curious incident of the dog in the night.
>
>
In the relational approach, what is a "search" except that it is nothing but a join? (on some attributes or none.) At a physical level, then, an index is one way to speed joins, but only one way. So I'd say that an rdbms requirement for searching doesn't necessarily imply a db requirement for indexes.
p Received on Tue Jun 06 2006 - 03:49:36 CEST