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 […]
Visual Normalization – Use the Power of the Dependencies
Click to learn more about author Thomas Frisendal. One of the major contributions of Dr. Ted Codd’s relational model is the focus on the importance of functional dependencies. In fact, normalization is driven by a modeler’s desire for a relation where strict functional dependency applies across all the binary relations between the designated primary key and […]
A Database Reverse Engineering Case Study
Click here to learn more about author Michael Blaha. In a blog last year we discussed database archaeology, which is another name for database reverse engineering. Database reverse engineering is the inverse to normal development. We start with an application and work backwards to understand the software and infer its content. This month we’ll take a […]
Foreign Keys and the Delete Performance Issue
Eventually you’ll run into a simple delete instruction that takes minutes (I mean, years!) to get executed. It’s just a hundred-row table, and, still, it takes a lifetime to get the rows deleted. Here’s a small tip: you’re probably missing some indexes. Foreign Keys and their dirty secrets There is a very basic, yet very […]