Does cascade happen in 1 transaction? - postgresql

Question

I save the Product which cascade persist the productMaterial. However, when the productMaterial throws DataIntegrityViolationException the product is rollbacked, which seems like cascade is done in 1 transaction, but i don't find any docs saying that it does. Can someone clarify it for me?
NOTE: I DO NOT use #Transactional
Material material = new Material();
material.setId(1);
Product newProduct = new Product();
ProductMaterial productMaterial = new ProductMaterial();
newProduct.setName("bàn chải");
newProduct.setPrice(1000);
newProduct.setCreatedAt(new Date());
newProduct.setProductMaterials(Collections.singletonList(productMaterial));
productMaterial.setProduct(newProduct);
productMaterial.setMaterial(material);
productRepository.save(newProduct);
Here is the hibernate execution:
Hibernate:
/* insert com.vietnam.hanghandmade.entities.Product
*/ insert
into
product
(created_at, name, price, id)
values
(?, ?, ?, ?)
2020-11-10 14:55:38.281 TRACE 65729 --- [nio-8080-exec-2] o.h.type.descriptor.sql.BasicBinder : binding parameter [1] as [TIMESTAMP] - [Tue Nov 10 14:55:38 JST 2020]
2020-11-10 14:55:38.281 TRACE 65729 --- [nio-8080-exec-2] o.h.type.descriptor.sql.BasicBinder : binding parameter [2] as [VARCHAR] - [bàn chải]
2020-11-10 14:55:38.281 TRACE 65729 --- [nio-8080-exec-2] o.h.type.descriptor.sql.BasicBinder : binding parameter [3] as [INTEGER] - [1000]
2020-11-10 14:55:38.281 TRACE 65729 --- [nio-8080-exec-2] o.h.type.descriptor.sql.BasicBinder : binding parameter [4] as [OTHER] - [e5729490-a0f8-48e7-9600-eeeba8b8f279]
Hibernate:
/* insert com.vietnam.hanghandmade.entities.ProductMaterial
*/ insert
into
product_material
(material_id, product_id)
values
(?, ?)
2020-11-10 14:55:38.324 TRACE 65729 --- [nio-8080-exec-2] o.h.type.descriptor.sql.BasicBinder : binding parameter [1] as [INTEGER] - [1]
2020-11-10 14:55:38.324 TRACE 65729 --- [nio-8080-exec-2] o.h.type.descriptor.sql.BasicBinder : binding parameter [2] as [OTHER] - [e5729490-a0f8-48e7-9600-eeeba8b8f279]
2020-11-10 14:55:38.328 WARN 65729 --- [nio-8080-exec-2] o.h.engine.jdbc.spi.SqlExceptionHelper : SQL Error: 0, SQLState: 23503
2020-11-10 14:55:38.328 ERROR 65729 --- [nio-8080-exec-2] o.h.engine.jdbc.spi.SqlExceptionHelper : ERROR: insert or update on table "product_material" violates foreign key constraint "product_material_material_id_fkey"
Detail: Key (material_id)=(1) is not present in table "material".

Answer 1

NOTE: This answer missed the point of the question, which is about “cascading persist” – it talks about “cascading delete” for foreign keys.
The cascading delete or update is part of the action of the system trigger that implements foreign key constraints, and as such it runs in the same transaction as the triggering statement.
I cannot find a place in the fine manual that spells this out, but it is obvious if you think about it: if the cascading delete were run in a separate transaction, it would be possible that the delete succeeds and the cascading delete fails, which would render the database inconsistent and is consequently not an option.