Data modelling is not the only limiter of performance. When I first started working with databases, performance in all aspects of computing was much worse than it is now. However well an expert might craft a query, and however simple the query might be, technical restrictions would always limit the performance to just a few [...]
A very common problem with databases is missing data. Missing data makes searches difficult (or impossible) and statistics unreliable. Two common reasons for this are: Records contain optional fields which have been left empty. Records are completely missing because some of the mandatory information was not available. Since the missing data was in mandatory columns, [...]
In this series of newsletters, we concentrate on data modelling in general and discuss relational databases when we need to consider specific applications. In general, we do not consider the so-called “NoSQL” databases. Relational database management systems lend themselves to the use of fixed schemas and also provide easy type checking. […]