Often the data we are modelling must be imported into a database. Data importing can be a complex and difficult task. Often the data must come from several different sources and the importing will occur in several steps. Sometimes the data for different tables can come from different sources and must be imported at different [...]
In a database, good performance is vital. So, how can we be sure we will have good performance in a project? What will make a data model good for performance or bad? And what is good performance anyway? Let’s start by defining good performance. […]
Use cases must be designed in cooperation with future users of the software or database. Designers will have a theoretical view to some extent, while users have more practical demands. Theoretical matters are not an end in themselves, so aim for practical solutions. […]
If you are going on a long hike; planning an overseas trip; building a new house; planting a garden; or doing many other things in life, one of the main questions is “What do I need?” Sometimes it is deciding what we need to take with us, while at other times it is deciding what [...]
Definition With software, a “use case” is a specific situation for which the software must be used to achieve a particular goal. Normally, this will be defined as a set of steps that must be followed to do the work. Use cases are invaluable for customers and suppliers alike. They help a supplier to understand [...]
At times we feel that we are getting everything right in one area of our work. Everything we touch seems to turn to gold and we feel completely happy with our decisions and achievements – in that area. But data modelling won’t let us work in only one area – ignoring all the bits we [...]
In some cases, when we begin a task of data modelling, we can build walls around our project and treat it as an independent kingdom. The design process is easier if the project has no need of any inputs from outside nor any need to provide information to anywhere else. This gives us much more [...]
How will my software be used in two years’ time? What extra fields should I add now so that they can be used in “a while”? Should I make these fields optional until some extra data is available next year? Is data validation necessary, or will it become a maintenance nightmare? […]
Whenever we start a new job or begin work on a new project, one of the hardest things to learn is what questions to ask. We have knowledge, we have expertise, but we don’t always know how to get the information we need so that we can apply our expertise. […]
Data Modelling User Interface Decisions We model data because we want to be able to present it to people in a way that is useful. The way in which we present the data will make it more useful or less useful. If the modelling is bad, good presentation may be difficult or impossible. But even [...]