I am approaching a project where I'll be having to implement a database with my boss; we're a very small start up so the work environment is deeply personal.He had given me one of the company databases before and it completely went against what I was taught (and read about) in school for RDBMS. For example, there are entire databases here that consist of one table (per independent database). One of those tables is 20+ columns long and for context, here are some of the column names from one table:lngStoreID | vrStoreName | lngCompanyID | vrCompanyName | lngProductID | vrProductNameThe point being is that where he should have individual tables that hold the entity data (name, size, date purchased, etc.) he shoves it all in one large table per database.I want to improve this design, but I am not sure why a properly-normalized and segmented data model would actually improve this product. While I am familiar with database design from college and I understand how to do it, I am unsure why this actually improves databases.Why does a good relational schema improve a database?
Why does the relational model for a database matter?
database;relational database
The performance argument is usually the one which is most intuitive. You especially want to point out how it will be difficult to add good indexes in an incorrectly normalized database (note: there are edge-cases where denormalization can in fact improve performance, but when you are both inexperienced with relational databases you will likely not easily see these cases). Another is the storage size argument. A denormalized table with lots of redundancies will require far more storage. This also plays into the performance aspect: the more data you have, the slower your queries will be.There is also an argument which is a bit harder to understand, but is in fact more important because you can't solve it by throwing more hardware at it. That's the data consistency problem. A properly normalized database will take care by itself that a product with a specific ID always has the same name. But in a denormalized database such inconsistencies are possible, so special care needs to be taken when it comes to avoiding inconsistencies, which will take up programming time to get right and will still cause bugs which will cost you in customer satisfaction.