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SQL Support for UML Associations

By   /  July 19, 2017  /  Data Blogs | Information From Enterprise Leaders, Data Modeling Blogs, Data Modeling News, Articles, & Education, Database Blogs, Database News, Articles, & Education  /  No Comments

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 […]

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Data Interchange Models: What are They?

By   /  June 16, 2017  /  Data Blogs | Information From Enterprise Leaders, Data Modeling Blogs, Data Modeling News, Articles, & Education, Database Blogs, Database News, Articles, & Education  /  No Comments

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 […]

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Enterprise Data Modeling

By   /  May 12, 2017  /  Data Blogs | Information From Enterprise Leaders, Data Modeling Blogs, Data Modeling News, Articles, & Education, Database Blogs, Database News, Articles, & Education  /  No Comments

Click to learn more about author Michael Blaha. 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. What Is an Enterprise Data Model? An […]

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Identity: Working with Surrogate Keys

By   /  April 14, 2017  /  Data Blogs | Information From Enterprise Leaders, Data Modeling Blogs, Data Modeling News, Articles, & Education, Database Blogs, Database News, Articles, & Education  /  2 Comments

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 […]

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Softcoded Data

By   /  February 27, 2017  /  Data Blogs | Information From Enterprise Leaders, Data Education, Data Modeling Blogs, Data Modeling News, Articles, & Education, Database Blogs, Database News, Articles, & Education  /  No Comments

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. […]

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Debugging Complex SQL Queries

By   /  January 25, 2017  /  Data Blogs | Information From Enterprise Leaders, Data Education, Data Modeling Blogs, Data Modeling News, Articles, & Education, Database Blogs, Database News, Articles, & Education  /  2 Comments

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. […]

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Database Reflections: Ten Things to Consider

By   /  January 9, 2017  /  Big Data Blogs, Big Data News, Articles, & Education, Data Architecture Blogs, Data Architecture News, Articles, & Education, Data Blogs | Information From Enterprise Leaders, Data Education, Data Modeling Blogs, Data Modeling News, Articles, & Education, Data Strategy Blogs, Data Strategy News, Articles, & Education, Database Blogs, Database News, Articles, & Education, Enterprise Information Management, Information Management Blogs  /  2 Comments

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 […]

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Be Careful with Derived Data

By   /  December 5, 2016  /  Data Blogs | Information From Enterprise Leaders, Data Education, Data Modeling Blogs, Data Modeling News, Articles, & Education, Database Blogs, Database News, Articles, & Education, Enterprise Information Management, Information Management Blogs  /  2 Comments

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 […]

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Data Warehouse Model: Diffuse Relationships

By   /  October 26, 2016  /  Data Blogs | Information From Enterprise Leaders, Data Education, Data Modeling Blogs, Data Modeling News, Articles, & Education, Enterprise Information Management, Information Management Blogs  /  No Comments

Click here to learn more about author Michael Blaha. A diffuse relationship is one of a group of similar relationships, which broadly apply to entities in a model. We can show them explicitly, but such an approach can become verbose and obscure the deeper content of a model. We coined the term “diffuse relationship” as […]

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Beware of Symmetric Relationships

By   /  September 28, 2016  /  Data Blogs | Information From Enterprise Leaders, Data Education, Data Modeling Blogs, Data Modeling News, Articles, & Education, Enterprise Information Management, Information Management Blogs  /  No Comments

Click to learn more about author Michael Blaha. A symmetric relationship is a self-relationship with the same multiplicity and role name on each end. Symmetric relationships are acceptable for conceptual models. But they are problematic for logical and physical models – you should rework the model to eliminate them. An Example For an example, consider […]

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