JPA Hibernate deleteAll(List<T> entities) not working as expected

Question

I am trying to batch delete n objects with JPA repository deleteAll(List entities), and it works. But at the end it produces n queries to the database instead of grouping elements by the batch size.

Expected behaviour:

• 20 entities to delete
• batch size 10
• queries to the database 2

Actual behaviour:

• 20 entities to delete
• batch size 10
• queries to the database 20

If I do the batch update saveAll(List entities) I am getting expected behaviour with 2 queries produced.

Answer 1

deleteAll(List entities) will delete all objects in one session, so the number of queries will be the n, grouped by the batch_size.

Answer 2

By default deleteAll not support for batch operations it will iterator each object and hibernate will do the deletion you can check in the console logs(hibernate delete query).

For the batch deletion you can use below method. deleteAllInBatch();

Reference - https://docs.spring.io/spring-data/jpa/docs/current/api/org/springframework/data/jpa/repository/JpaRepository.html#deleteAllInBatch-java.lang.Iterable-

Answer 3

Extend your repository from JpaRepository and try using deleteAllInBatch(List entities);