What are the most common types of databases for web applications?

Question

Some databases store objects, relational structure of tables, hierarchies, etc. What are all these types (models)? When is each application indicated (besides, of course, the developer’s preference)? Examples of each one?

Answer 1

Fired the most used is the model relational that has been there for more than 40 years serving very well almost all computing problems that require data storage.

Other models are being used more recently on sites that need a lot of scalability or by those who follow the paradigm of orientation to the modinha. That is, the person does not need it, but uses it because he saw that there are a lot of people using it. The main: value key (question here), object-oriented, graphs, hierarchical.

I’m not saying that at specific points they’re not useful.

There are different ways to implement these models, one of the most used in some systems is the document-based hierarchical (some specifically as XML) and the columnists.

When the data does not have a defined structure, it works well as a document and has no relation can be more interesting to use the document model, even if in conjunction with the relational.

When there is no defined structure, it will probably be very different, there are no relationships and the data work alone, key-value may be more appropriate. It is often used only as cache and not the main database.

Many of these models don’t allow raw performance. They can even respond fast by putting hardware that helps be fast. They usually climb better, or at least easier to climb.

These two forms are the most used when not using the relational model.

These models aren’t usually ACID which can be preventing in many cases. Some to be ACID give up advantages by which they are chosen.

In general they are called Nosql, which is a misnamed. See How to choose between Nosql and SQL?.

In fact the leading market database brands that have always been relational have started to have mechanisms to work better with other models as well. So a hybrid database gives you the best of both worlds. They always allowed the document model, key-value and other models, but it was never simple, never had anything ready, now have, in most of them.

Some sites are so simple that they even use management systems and prefer a simple file system.

I don’t really like rankings of this kind, but there is DB-Engines to see the most used, according to their criteria (do not trust too much, it is only a basis). And has the tendency of asking more in Soen.

Note that only non-relational Mongodb have relevance, curiously one that has very little advantage over traditional Dbs that have modernized.

The fact is that people end up complicating what is simple. Here’s a little opinion: why use something you don’t need? To do the basic, worry-free integrity, performance, facilities to obtain data in various ways Nosql may be easier to develop for him, even where he is not really needed, But when you start asking for these characteristics, the relational model starts to stand out, and most problems need this model. As a database I only see the advantage of using these models when it needs database distribution, especially after relational models have started to adopt other models in an integrated way.

The hybrid model provided by the major relational Dbs seems to be a victorious model. Other models may be more suitable in niches.

There is a lot done with web interface but that does not matter for the database. In general there is abuse of web making which would work best as native application.

• What is a Nosql Bank? How it works?
• Nosql is as problematic as it seems?