Author: Bob Lambert
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Requirements Half-Life
I had pondered writing a post called “Requirements Decay” about how requirements don’t last forever. In my research I found that such a post, complete with “my” words “requirements decay” and “requirements half-life”, had already been done comprehensively here. In a compact argument underpinned by half-life mathematics, the anonymous author proposes that a requirement isn’t likely…
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Three things about “Interview with a Data Scientist”
Recently, I posted “Interview with a Data Scientist” at my company’s blog site. In it, my friend and colleague Yan Li answers four questions about being a data scientist and what it takes to become one. In my view Yan’s responses provide a bracing reminder that data science is something truly new, but that it rests on…
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To SQL or to NoSQL?
Recently there was a great post at Dzone recounting how one “tech savvy startup” moved away from its NoSQL database management system to a relational one. The writer, Matt Butcher, plays out the reasons under these main points: Our data is relational We need better querying We have access to better resources Summing up: “The bottom…
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DIY Data Dictionary: ODBC Reporting from the ERwin Metamodel
Application developers and business people accessing relational databases need data dictionaries in order to properly load or query a database. The data dictionary provides a source of information about the model for those without model access, including entity/table and attribute/column definitions, datatypes, primary keys, relationships among tables, and so on. The data dictionary also provides…
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Technical Interviewers: Seek Opinions Not Facts
Asking fact questions in technical interviews is like eating a donut, feels great at the time but not so satisfying later. Let’s say the interview consists of facts like this “softball question”: “What is the default port number for SQL Server?” The linked list of questions is a really good high level study guide for…
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How To Do Well in Your Next Job Interview
Recently I read an editorial about job interviews. It was breezy and funny, but not very helpful. Given that millions are out there looking for work, I want to help by giving my perspective on how to “win” the interview. I do a lot of interviewing, from both sides of the desk. As a consultant…
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Guiding Principles for Data Enrichment
The data integration process is traditionally thought of in three steps: extract, transform, and load (ETL). Putting aside the often-discussed order of their execution, “extract” is pulling data out of a source system, “transform” means validating the source data and converting it to the desired standard (e.g. yards to meters), and load means storing the…
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Get the Big Picture: Effective High-Level Diagrams
I believe that early, effective big picture diagrams are key to application development project success. According to the old saw, no project succeeds without a catchy acronym. Maybe so, but I’d say no project succeeds without a good big picture diagram. The question: what constitutes a good one? To me good high-level diagrams have four key characteristics:…
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Thoughts on Healthcare Data Quality
The well-publicized problems with healthcare.gov are disturbing, especially when we remember they might result in many continuing without health insurance. But it seemed a step in the right direction when recent a news report differentiated between “front end” and “back end” problems. The back end problems were data issues, like a married applicant with two…
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Business Intelligence Requirements: The Payoff’s in the Details
A technique for reporting requirements has emerged as the de facto standard in the business intelligence community. The technique, which emerged in the mid-2000s, is new enough to be as yet unacknowledged by the requirements analysis powers that be. David Loshin describes how it works in this 2007 post: Start with a business question about…