Tips for Mastering Data Modeling
Data modeling refers to the process where by data is structured and organized. It is a key component in the field of computer science. Once data is structured, it is usually then implemented into what is called a database management system. The main idea behind these systems to manage vast amounts of structured and unstructured data.
Unstructured data include documents, word processing, e-mail messages, pictures, and digital video and audio files. Structured data – what is needed to make a data model (via a data model theory) – is found in management systems like relational databases. A data model theory is the formal description of a data model.
Data models are highly flexible structures that can be employed to meet a variety of ends. In same ways, the process of data modeling can be compared to class modeling, the difference being that whereas in class modeling, classes are identified, in data modeling, types are identified.
The data model serves two main functions. First off, it needs to serve as an accurate representation of the analyst’s understanding of the overall enterprise. This way, the customer will be able to judge rightly whether or not the analyst understood the project. It is the ultimate test to see if the analyst really understands the nature of the business. If a data model is executed properly, then the answer will be quite clear. It should ask the user if it fulfills what he or she desires.
Next, the data model must provide an accurate reflection of the organization’s data. As such, it will provide the best starting point for the design of a database. While the final database design may very well end up looking a lot different than the data model, the data model should always strive to resemble the finished structure. This makes it easier to perform any necessary adjustments along the way. The designer/builder should get the message from the model – this is what you want to build.
Below, you will find some useful tips for building effective data models.
-When you’re naming the entities, aim for clarity and cohesion. Make sure the name is a clear representation of the thing. By using normal English (or Spanish, whatever language you’re working in), you eliminate a lot of confusion in advance. It is also to keep in mind who you’re designing the model for, i.e. your audience. Therefore the entity names should be universally recognizable by all. Steer clear of acronyms, table names, and abbreviations. Accompany each entity name with a concise, clear definition in the dictionary.
-If you have not had time to analyze an identified entity, be sure to state that in the dictionary. Try to come back to it as soon as possible. You should strive to identify all possibly relationships.
-Each time an entity occurs, it should be marked with the use of a sub-type. Each entity’s occurrence should only appear in that singular sub-type. Never use a sub-type where an example would function better. Using a sub-type implies that it has relationships that distinguish it from others and that the division of entities into sub-types is a stable form of organizing the data.
-Weak relationship names should be avoided at all costs. You don’t need to use statements like related to; the fact that it is a relationship makes this point pretty clear. A gerund can be employed if need be, but only as a last resort. In general, concreteness should always be striven for, so that the client may easily correct it if it is not 100% accurate.
-The drawing should be organized in a way so that it will be attractive visually. Always give equal weight to both sides of the diagram. White spaces should be left with discretion. Make sure different elements are not crowded together unless they absolutely have to be.
-The overall model should be broken into different topics. That way, each diagram only concerns at most two subjects. The drawings should be organized in a way that each one represents a whole “logical horizon.”
– If you are building a model for publication, laying it out in “portrait” is a lot better. But if it’s just for the screen, choose “landscape” form – it is a lot more efficient. Whatever you choose, make sure it is used consistently throughout all the diagrams.