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 …
Here are three additional levels of numerology that just don't belong the discipline of software architecture.
Empiricism. Ideally these are from Physics and related "hard" sciences. Psychology or Economics are "hard" sciences in the other sense of hard -- they're difficult because of the subject matter. The magic number 7 ± 2 …
more ...The company, W, is an e-business startup with a successful, profitable business operation. They were using a mixture of PCs and small servers from various sources to conduct business. They had a base of customers, a positive cash-flow and investment dollars.
W contacted two large software and services companies …
Having problems with possibly the dumbest strategy of all time. It's difficult to work around because it comes from a management interrupt, and all my lands are tapped out. I've got nothing left to do except to sit around and watch bad things happen.
It's not the whole crew; it's …
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