Re: Pizza Example
Date: Tue, 6 Apr 2004 09:47:18 -0400
You make several points. Let me se if I can sort them out.
The upper limit on descriptive names like "Pizza" does not exist for the same reason that the upper limit exists on fixed length data items. Good point.
In the discussion, the issue of whether names are data or not has been raised. When I look at a supermarket checkout receipt, I use the descriptive name for informative purposes, to identifiy an object that is in the bag, and relate it to an item that was on my shopping list. I'm using the way I use data. It's not clear that a data processing system ought to be able to do the same.
Some constraints exist to protect the integrity rules. Good point. The reason we don't validate the SSN by referential integrity is simple: we don't have the master SSN column in our database.
You prefer that the more important constraints be handled by the application programmers rather than the DBA. Questionable point. I have been to a lot of sites, and I have seen two cultures with regard to the DBA. In one culture, the DBA is concerned with efficiency, throughput, security, and data corruption from computer malfunction, but not with the meaning of the data. That's in the hands of an application manager.
In other cultures, the DBA is the custodian of the shared data, not only from the point of view of the physical state of the data, but also from the point of view of its adherence to the logical model. If we need a new column in an existing table, we go to the DBA. And the DBA has, in this culture, veto power over our request, because it's part of his responsibility to future users.
I can't tell you which culture is "better". I can only tell you that both exist and function.
And a DBA is not the same thing as a DB designer, in either culture. Received on Tue Apr 06 2004 - 15:47:18 CEST