> For the complete documentation index, see [llms.txt](https://db.jodd.org/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://db.jodd.org/jtx/db-and-annotations.md).

# Db and Annotations

*JTX* supports multiple resource types, but its most efficient with single resource type, such as relational database. Therefore, there is whole layer build on top of generic *JTX* classes that serves just to simplify use and usage of transaction over databases.

### Declarative transactions

But that is not all. Transactions, in general, are a perfect example of scattered logic, that can be encapsulated via aspects. With help of *Proxetta*, *JTX* can be applied on methods that are annotated with `@Transaction` annotation.

#### Custom transactions

In most applications we would have only two types of transactions: one that only read and one that allows writing data. `@Transaction` annotation by default matches read-only transactions, meaning that on every place where read-write transaction is needed, user have to write this with annotation elements.

To reduce this boilerplate code, it is possible to define custom annotation that takes different default values.