Weird behavior after retrieving select

[Red44]

When logging with p6spy [basically a JDBC man in the middle attack], it becomes apparent, that every select done by springboot jpa/hibernate is followed by a bunch of validation statements resulting in an N+1 problem, that hasn't been noticed, because the normal hibernate logging framework seems to hide them.
p6spy shows that each of these checks take something between 0.2 and 0.5ms depending on your resultset, performance issues arise.

Proof

[quaff]

Because you are using assigned ID generator and not implementing isNew(), Spring Data JPA assume it's not new using entityManager.merge() instead of entityManager.persist(), merge will issue a select first to decide insert or update.

https://github.com/spring-projects/spring-data-jpa/blob/main/spring-data-jpa/src/main/java/org/springframework/data/jpa/repository/support/SimpleJpaRepository.java#L618-L628

[Red44]

https://github.com/spring-projects/spring-data-jpa/blob/main/spring-data-jpa/src/main/java/org/springframework/data/jpa/repository/support/SimpleJpaRepository.java#L618-L628

I am not talking about the save method or that that will be executed multiple times. I just did that to get some sample data into the db. It's about these weird statements after the select.

[mp911de]

First of all, there is only a single SELECT statement being logged, the remaining statements show result rows.

Second issue is that Hibernate has to run a SELECT, how else is it supposed to fetch data?

All this is expected and since Spring Data JPA isn't running any SQL on its own, rather it uses an underlying JPA provider, all subsequent statements are subject to your JPA provider.