The answers here are not complete!
First off, let’s check the documentation!
void deleteInBatch(Iterable<T> entities)
Deletes the given entities in a batch which means it will create a single Query.
So the “delete[All]InBatch” methods will use a JPA Batch delete, like “DELETE FROM table [WHERE …]”. That may be WAY more efficient, but it has some caveats:
- This will not call any JPA/Hibernate lifecycle hooks you might have (@PreDelete)
- It will NOT CASCADE to other entities
- You have to clear your persistence context or just assume it is invalidated.
That’s because JPA will issue a bulk DELETE statement to the database, bypassing the cache etc. and thus can’t know which entities were affected.
See Hibernate Docs
The actual code in Spring Data JPA
And while I can’t find a specific article here, I’d recommend everything Vlad Mihalcea has written, to gain a deeper understanding of JPA.
TLDR: The “inBatch” methods use bulk DELETE statements, which can be drastically faster, but have some caveats bc. they bypass the JPA cache. You should really know how they work and when to use them to benefit.