What are common misconceptions about database normalization?

People often think that normalization always improves database performance. While normalization reduces redundancy and ensures data integrity, it can also result in complex queries requiring multiple table joins, perhaps delaying read processes. It's essential to balance performance considerations with normalization. Sometimes, denormalization is used in read-heavy systems to improve efficiency.

I'll add that I've seen a lot of databases designed around an abstract self referencing object stored in a single table. That object could be folder that is a part of hierarchy tree, that object could be a collection that is a child of a folder object. That object could also be a property of a object that exists in that collection. Some developer's mouth is watering at this abstract object that can do all and has one single handler on the API side. It's cool but it's not very readable. You'll see people struggle to write simple queries against such a database. RDMBS can be laborious to work with and I'm seeing a trend away from creating first class objects and building tables and the CRUD operations to support them.

3NF Normalization is great for reducing redundancy and keeping tables “clean” as everything is about the key, the whole key, and nothing but the key. In reality, we sometimes have denormalize for better performance such creating a report table for a resource intensive report when you’ve exhausted all the other options. So, yes balance is a major part of any database environment.

Over-normalization is bad, and can lead to excess queries. It is important to note that there's no one size that fits all approach.

I agree with the statement above. As in all other endeavors, perfection is a sought after yet never achieved. Performance optimization can lead to variations in database structures that can appear to violate normalization requirements but in the end performance is key.

Data quality and database performance are two different sides of ensuring good data specially when reporting is in question, but in transactional oriented DB's for reporting You have to meet somewhere in between transactions and repoeting.

If you have a product database that includes the product name, description, and price, you may have multiple entries for the same product if it comes in different colors or sizes. Thereby, making a normalized data to ensure that the same information is stored in only one place, which will help to reduce the chances of errors.

La normalización de bases de datos es un concepto muy poco comprendido. Está operación es esencial para la estructuración correcta de los datos con base en las llamadas "formas normales". Además, una base de datos higienizada y validada puede responder frente a usos no permitidos o maliciosos. Hay vida antes de los lenguajes de programación visuales e incluso del mismo SQL. Y se llama "Normalización y Limpieza de Bases de Datos".