Re: Dreaming About Redesigning SQL
From: Marshall Spight <mspight_at_dnai.com>
Date: Thu, 23 Oct 2003 08:26:58 GMT
Message-ID: <mhMlb.2417$9E1.18525_at_attbi_s52>
> All physical structures will bias performance for some operations and
> against others.
Date: Thu, 23 Oct 2003 08:26:58 GMT
Message-ID: <mhMlb.2417$9E1.18525_at_attbi_s52>
"Bob Badour" <bbadour_at_golden.net> wrote in message news:W46dnf4tbfF1DwiiU-KYgw_at_golden.net...
>
> All physical structures will bias performance for some operations and
> against others.
This strikes me as a succinct statement of the value of data independence. One has the option (but not the requirement) to adjust the physical structures the DBMS uses while keeping the logical model (and therefor all application code and queries, etc.) unchanged.
Unless one has data independence, one does not have this option; one will be locked into a particular performance model. This is why I found the MV guy's obvious pleasure at being able to precisely describe the performance model for his DB as odd: I thought it a deficit to be able to say what it was; he thought it an asset.
Marshall