Let Hibernate detect the dialect to use

[snicoll]

Spring Boot detects the dialect to use based on the DataSource. Unfortunately, the defaults in framework are quite conservative and Hibernate is doing a good job at detecting the right dialect anyway.

As suggested in #15342 (comment) we should stop doing that upfront and let Hibernate do its thing.

[viktoriya-kutsarova]

@snicoll If this issue is suitable for contribution, I can try to tackle it.

[snicoll]

Thanks for the offer. The issue is assigned and therefore not opened for contribution. I've assigned myself as there are quite a lot of things to consider.

[trajano]

I don't think this is working yet. I put a breakpoint on StandardDialectResolver and I found that it is not being hit with spring-boot 2.1.7

[snicoll]

@trajano that's because this was fixed in Spring Boot 2.2. Perhaps you're looking at github on your phone and you're missing the column that provides the milestone on the right?