Query performance regressions in Hibernate 6

Hibernate ORM
37

@beikov: I saw your performance improvements on the main branch. My original test looks much better and is on par with Hibernate 5.

Our indexer is slightly faster now, but still significantly slower than with Hibernate 5.

I adjusted my tests to more closely resemble one of our core entities and discovered another major regression:

Hibernate 5.6:

Test-case 1: Query took 12.9S
Test-case 2: Query took 18.6S

Hibernate 6 (Main):

Test-case 1: Query took 27.9S
Test-case 2: Query took 36.9S

All I did was add an eager one-to-one AuthorDetails association to the Author entity.

Could you do one more round of profiling on the updated test-cases?