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I’m going to do something different this month and reflect on some observations of the IT industry. My comments will focus on database-related topics. This is a smattering of ideas that is not intended to be comprehensive. I’m hoping that this article will stimulate dialogue. I welcome comments on my opinions as well as your own insights.
Continue reading IT Reflections
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The UML is a popular notation for modeling software. Even though the UML was mostly developed for programming, it is also relevant for databases. This article takes a critical look at using the UML for databases.
Continue reading When To Use the UML for Databases
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Here’s a chapter from my book Patterns of Data Modeling. This chapter presents six data modeling patterns for trees — UML data models, IE data models, SQL queries, and examples. The book has much more information about patterns including patterns for directed graphs, patterns for undirected graphs, antipatterns, and archetypes.
It’s been 25 years since these GE Research folks published “Object-Oriented Modeling and Design.” From left to right, Bill Lorensen, Jim Rumbaugh, Mike Blaha, Bill Premerlani and Fred Eddy. We had no idea at the time that the book would sell over 200,000 copies.
Here is an example of a UML (Unified Modeling Language) data model. This is from my Infinite Skills video course Learning Data Modeling. The model was created with the Enterprise Architect tool by Sparx Systems. This corresponds to the IE data model.
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A use case is a piece of functionality that an app can perform. Each app has many use cases and the use cases taken collectively specify the app’s functionality. For an example, consider an app for tracking library loan records. Some use cases are: borrow books, borrow magazines, return books, return magazines, renew books, renew magazines, pay fines, get library card, and change address.
Continue reading Use Cases Are Overblown