Click to learn more about author Michael Blaha. This will be the last blog I write for DATAVERSITY® as I am dealing with health issues. I have cancer but am fortunate to be receiving excellent medical care. With treatment my prognosis is good, but this affects my free time. Hence this will be my last […]
SQL Support for UML Generalizations
Click to learn more about author Michael Blaha. This blog continues last month’s UML theme. Last month we discussed UML associations. Now we’ll discuss UML generalizations. The UML (Unified Modeling Language) is a popular modeling notation that arose from the programming community, but it is also applicable to databases. The UML has a variety of […]
SQL Support for UML Associations
Click to learn more about author Michael Blaha. The UML (Unified Modeling Language) is a popular Data Modeling notation that arose from the programming community, but it is also applicable to databases. The UML has a variety of models, one of which is the class model. The UML class model is essentially just a dialect […]
Data Interchange Models: What are They?
Click to learn more about author Michael Blaha. Let’s continue last month’s discussion about different kinds of data models and look at data interchange models. My interest in this topic was piqued by several encounters with overly complex data interchange models. Data Interchange Model A data interchange model provides the means to convey data among […]
Enterprise Data Modeling
It’s important to have data models guide the development of individual applications and ensure that they meet business objectives. But it’s not sufficient. Other kinds of data models, such as enterprise data models, are also part of proper Data Governance. This article will explore the fundamentals of Enterprise Data Modeling. What Is an Enterprise Data […]
Identity: Working with Surrogate Keys
Click to learn more about author Michael Blaha. Identity is the means for denoting individual entities, so that they can be found. Identity is a prominent concern for databases because developers must have some way for referring to things. There are two aspects of identity – how to connect records together (internal identity) and how […]
Softcoded Data
Click to learn more about author Michael Blaha. Database applications typically have a direct representation. Application concepts are represented as tables with their attributes stored as table columns. This direct approach works well for applications with fixed structure. However, it fails for applications with structure that is not fully known as the application is being built. […]
Debugging Complex SQL Queries
Click to learn more about author Michael Blaha. We favor the offloading of application logic to SQL queries. Developers can save time, effort, and reduce mistakes by substituting SQL for programming code. This leads to lengthy and complex SQL that must be debugged. It is common to write a SQL query that initially fails to execute. […]
Database Reflections: Ten Things to Consider
Click here to learn more about author Michael Blaha. 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 […]
Be Careful with Derived Data
Click here to learn more about author Michael Blaha. We often perform database reverse engineering as part of our consulting work. We have found that it’s common for databases to contain derived data. Derived data is data that can be computed from other base data. Often, the storing of derived data is a mistake and […]