In principle, stating a problem is a trivial exercise: someone can't do something. It can be made wonderfully complex, however. The root cause of the complexity could be a fundamental unwillingness to state the problem without including technology hints like "database" or "hierarchy" or "project management" or "change control".
"Polymorphism is nice as well, although I can't grok (yet) why this is necessarily not part of non-OO things. I'm not clear that it goes with the strong binding of state and method in a class."
Polymorphism isn't necessarily part of OO. Python actually has polymorphic functions outside of class …
more ...The "correct" answer is to fully normalize the design and get away from a mixed bag of columns and nulls. The MESS is bad from every perspective, except query performance. A semi-normalized design that separates the STATE CHANGES from the ESSENTIAL DEFINITION is an optimal design in many respects.
Here …
more ...Experimental results depend on details of the database server and the data model used. Actual application software may have other confounding problems that make these results less dramatic or more dramatic when applied to a existing application design.
I compared three table designs described in a previous posting Normalization Experiment …
more ...Fragmentation & similar is sometimes a storage problem in I/O generated, vs. the gross space consumed. This distinction didn't leap out at me.
Performance degradation and storage expansion are closely related, but only for certain kinds of queries. Full table scans are penalized by sparsely used storage. Individual row retrievals …
more ...The open question is "What is the cost of fragmentation?"
The cost has some absolute components and some relative components. Since fragmentation is difficult to avoid except through grotesque over-allocation of space, the issue is to control fragmentation through normalization. A more important pair of questions, then, are these:
"How do we prevent storage fragmentation and the associated slow-down ?"
Why prevent ?
This is hard to respond to. The ounce-of-prevent-pound-of-cure didn't resonate with the reviewer. What would resonate? An in-depth discussion of the "prevention is an investment with an indefinite period of return and correction is an ongoing cost" doesn't …
more ...Perhaps this is heresy. Perhaps it merely shows that the orthodox may be focused on short-term delivery, not long-term value.
The client has a table we could describe as following the M.E.S.S. -- Multiple Entity Sub-Species -- design pattern. The hallmarks of this design are a …
While the intent of the use case technique is clear, it requires some discipline and creativity to execute successfully.
There seem to be three attractive sinks for time and energy.
Stepping In Sequence. Often, the first use cases developed are often those that occur “early” in the business process …
The company, H, is a large, well-established financial services firm. In order to meet regulatory reporting requirements, they elected to build a data warehouse that would integrate information from 40 applications to feed an application that would produce the regulatory reports.
H put together a team of business analysts …