Re: database market share 2003

"Mark Townsend" <markbtownsend_at_comcast.net> wrote in message news:5raAc.48687$eu.47179_at_attbi_s02...
>
> > With Oracle (a little more than some other RDBMS's) programmers and
users
> > who access the data want to know (or need to know depending on your
point of
> > view) a little bit about the way the data is physically organized. This
> > includes things like rowids, certain kinds of indexes, etc. In a pure
> > relational model, the physical structure of the data is isolated from
the
> > logical structure.
>
> I'm still confused - you mean product specific features/techniques that
> improve performance but are not a pure relational model and/or part of
> the ANSI SQL Standard ? Perhaps some of the things mentioned in articles
> like
>

http://www-106.ibm.com/developerworks/db2/library/techarticle/0204pooloth/0204pooloth.html
> Or this
>

http://www-106.ibm.com/developerworks/db2/library/tips/dm-0403wilkins/index.html#appendixb
> Or this
>

http://www7.software.ibm.com/vadd-bin/ftpdl?1/vadc/dmdd/db2/dm-0312stolze/0312stolze.pdf
> Or this
>

http://www-106.ibm.com/developerworks/db2/library/tips/dm-0312yip/index.html
> Or the "Resolving Lock Problems" section of this
>

http://www-106.ibm.com/developerworks/db2/library/techarticle/0310wilkins/0310wilkins.html
> Or this
>

http://www-106.ibm.com/developerworks/db2/library/techarticle/0306arocena/0306arocena.html
> Or this
> http://db2mag.com/db_area/archives/2003/q2/welgan.shtml
> Or this
> http://www.db2mag.com/db_area/archives/2003/q2/deng.shtml
> Or this
> http://www.redbooks.ibm.com/redbooks/SG246917/css/SG246917_bmark.html#
> or this
>

http://www-106.ibm.com/developerworks/db2/library/techarticle/0303kuznetsov/0303kuznetsov.html
> Or this
>

http://www-106.ibm.com/developerworks/db2/library/techarticle/0302kuznetsov/0302kuznetsov.html
> Or this
>

http://www-106.ibm.com/developerworks/db2/library/techarticle/0301mullins/0301mullins.html
> Or this
>

http://www-106.ibm.com/developerworks/db2/library/techarticle/0208kuznetsov/0208kuznetsov.html
> Or this
>

http://www-106.ibm.com/developerworks/db2/library/techarticle/0208zubiri/0208zubiri.pdf
> Or this
>

http://www-106.ibm.com/developerworks/db2/library/techarticle/0203milligan/0203milligan.html
>

No, that is not what I mean, nor what Ted Cod meant. Simply improving performance does not make the database less relational to Codd

If the end user or programmer is required to, or benefits from, knowing the physical structure of the data, or can use SQL extensions to improve performance, then these extensions to the SQL model move away from the pure relational model. Oracle has more of these features than DB2, which they publicize heavily when arguing that Oracle is superior to DB2.

When performance is increased behind the scenes by the DBA, that does not necessarily violate Codd's 12 rules for the relational model.

In pure relational theory, knowledge of the physical structure of the data is isolated from the DML created by the end user to access the data. No relational databases evaluated by Codd passed all of his 12 rules, and maybe those that are still around pass even fewer of the 12 rules today than they did when he first evaluated them.

Very few people today really care whether a database is relational. The main criteria the "market share", so that the IT person will have more job opportunities open to them. All of the big 3 database will get the job done with about the same performance. Obviously SQL Server is limited to Windows only, which is another factor. Price is also a factor for the executives who pay the bills.

No one believes that MS or IBM will stop supporting their database products during our lifetime. So all this talk about market share is really just looking out for the personal interests of the IT people, disguised as something else.

If one were considering a database other than the big 3, then maybe it might a concern about how long the database product can survive in the market place, and how long it will be supported by in the future (by a company other than CA who will extract blood for a support contract). Received on Thu Jun 17 2004 - 02:21:32 CDT