micronaut-data | Ahead of Time Data Repositories | SQL Database library

I'm making a small endpoint and it doesn't work for me. It is very simple, and for this I am using micronaut

My pom.xml

I have kotlin & Micronaut application connecting to postgresql using r2dbc for reactive approach

I'm using micronaut-data-hibernate-jpa and I have one-to-many relation Parent-Children. I'm trying to save parent entity with list of children by save operation on parent repository. Parent and children are saved but child don't have parent id saved in database.

My Entities are defined like this:

I am trying to create a sample application using micronaut framework. I have created a repository class that extends JPA repository

I'm studying Micronaut and Kotlin using gRPC for a project at work, and I've ran into some problems that I can't seem to find a answer to.

I'm recriating some personal Spring projects in Micronaut using Kotlin. In those projects I create a custom bean validator annotation to verify if a parameter is duplicated or not. I've recriated it in Kotlin but it's never called, I've also debbuged the code, and it never stops at the breakpoints in the validator.

Here's my Entity class that I want to validate. Note the @UniqueEmail annotation, that's my custom validator.

I'm trying to create a Micronaut function application with JPA support.

build.gradle.kts

According to micronaut-data reactive guide,

"... In the case of reactive execution and if the backing implementation is blocking, Micronaut Data will use the Configured I/O thread pool to schedule the query execution on a different thread.

If the backing implementation natively supports reactive types at the driver level then the I/O thread pool is not used and instead it is assumed the driver will handle the query in a non-blocking manner..."

My straight question: accessing a Relational Database (eg. PostGres R2DBC driver) throw R2DBC will Micronaut Data rely that R2DBC driver will handle in a non-blocking manner and be more scalable?

Supposing my microservice expose a Reactive endpoint based on ReactiveX and has to access a blocking data source throw Micronaut Data JDBC (eg. there isn't yet Oracle R2DBC in production version), it is clear from above that it "will use the configure I/O thread pool" while accessing data. Am I losing totally the benefits o Reactive endpoint?

It is my first project with Micronaut and I have few ones with Reactive approach. I am far to be an expert in Reactive best practices but I remenber have read in several blogs: avoid use reactive stack if you have blocking source. I also remember read that you can have worse result mixing non-blocking with blocking design mainly because the way Eventloop (eg. Netty) is designed. Since I will use Micronaut with ReactiveX and Relational Database, some cases with R2DBC and others with JDBC, I will gratefull any comment on my doubt.

Context: I am using Kotlin with Micronaut and for this project I will not add Spring dependencies.

I created successfully a Hello Word enpoint and I can post to it from Postman. The issue started when I evolulated the data to have birthday (java.time.LocalDate).

Copied from Postman

I want to use io.micronaut.data.repository.CrudRepository. In IntelliJ, even after I added the dependencies I get a complain: Unresolved reference CrudRepository

As far as I can see I added the io.micronaut.data:micronaut-data-hibernate-jpa as expected for Crudrepository