Spring data jpa insert into multiple tables to avoid locking tables

Can you please help me understand how to insert entities into multiple tables efficiently?

I have 3 tables and 3 entities accordingly. Pricebook has an array of SKUs, and each SKU has 1 price. Basically what I want is to insert multiple entities transactionally, in case of constraint I must update entities in a chain.

The problem occurred once I try to insert into DB more than 1 Pricebook in parallel, so I'm actually catching a PostgreSQL deadlock. I found a workaround is to insert them one by one putting them in the queue but I understand that it's not a great idea.

This might be a stupid question and has been already answered before, but I hope someone could give me a hint.

    @Entity
    @NoArgsConstructor
    @AllArgsConstructor
    @Table(name = "pricebook")
    public class Pricebook {
       @Id
       @GeneratedValue(strategy=GenerationType.AUTO) 
       private Long id;
       //....
    }

    @Entity
    @NoArgsConstructor
    @AllArgsConstructor
    @Table(name = "sku")
    public class Sku {
       @Id
       @GeneratedValue(strategy=GenerationType.AUTO)
       private Long id;
       //....
    }

    @Entity
    @NoArgsConstructor
    @AllArgsConstructor
    @Table(name = "price")
    public class Price {
       @Id
       @GeneratedValue(strategy=GenerationType.AUTO)
       private Long id;

       @JoinColumn(name = "pricebook_id", referencedColumnName = "id", unique = true)
       @ManyToOne(fetch = FetchType.LAZY, cascade = CascadeType.ALL)
       private Pricebook pricebook;

       @JoinColumn(name = "sku_id", referencedColumnName = "id", unique = true)
       @ManyToOne(fetch = FetchType.LAZY, cascade = CascadeType.ALL)
       private Sku sku;

       //....
    }

Here is PricebookService logic of an upsert.

  @NonNull
    @Transactional
    public Pricebook createPricebook(@NonNull CreatePricebookRequest request) {
        final Instant startDate = PricebookConverter.toDate(request.getStartDate());
        final Instant expirationDate = PricebookConverter.toDate(request.getExpirationDate());

        if (startDate.isAfter(expirationDate)) {
            throw new InvalidParametersException("The pricebook's start date later then its expiration date.");
        }

        final Region region = regionService.findRegionByName(request.getRegion());

        final Optional<Pricebook> isPricebookFound =
                pricebookRepository.findByRegionAndPricebookTypeAndStartDateAndExpirationDate(region,
                        request.getPricebookName(), startDate, expirationDate);

        final Pricebook savedOrUpdatedPricebook;
        if (isPricebookFound.isPresent()) {
            final Pricebook foundPricebook = isPricebookFound.get();

            savedOrUpdatedPricebook = pricebookRepository.save(
                    new Pricebook(foundPricebook.getPricebookId(), request.getName(), foundPricebook.getPricebookName(), foundPricebook.getRegion(), foundPricebook.getStartDate(),
                            foundPricebook.getExpirationDate());

            logger.info("pricebook is updated successfully, pricebook={}", savedOrUpdatedPricebook);
        } else {
            savedOrUpdatedPricebook = pricebookRepository.save(
                    new Pricebook(request.getName(), request.getPricebookType(), region, startDate, expirationDate);

            logger.info("pricebook is created successfully, pricebook={}", savedOrUpdatedPricebook);
        }

        final List<Sku> skus = skuService.createSku(savedOrUpdatedPricebook, request.getSkus());
        logger.debug("skus are saved successfully, skus={}", skus);
        return savedOrUpdatedPricebook;
    }

Here is SkuService logic of an upsert. skuToCreateOrUpdate basically is just a method wich wraps logic if it's found or new and return a new object.

    @NonNull
    public List<Sku> createSku(@NonNull Pricebook pricebook, @NonNull List<CreateSkuRequest> skus) {
        return skus.stream().map(sku -> {
            final Optional<Sku> foundSku = skuRepository.findByCode(sku.getCode());

            final Sku savedOrUpdatedSku = skuRepository.save(skuToCreateOrUpdate(sku, foundSku.map(Sku::getSkuId).orElse(null)));

            final List<Price> prices = priceService.createPrices(pricebook, savedOrUpdatedSku, sku.getPrice());
            logger.debug("prices are saved successfully, prices={}", prices);
            return savedOrUpdatedSku;
        }).collect(toList());
    }

Here is PriceService logic of an upsert.

    @NonNull
    public List<Price> createPrices(@NonNull Pricebook pricebook, @NonNull Sku sku, @NonNull CreatePriceRequest price) {
        final Optional<Price> foundPrice = priceRepository.findByPricebookAndSku(pricebook, sku);

        final Price savedOrUpdatedPrice;
        if (foundPrice.isPresent()) {
            final Price priceToUpdate = foundPrice.get();
            savedOrUpdatedPrice = priceRepository.save(
                    new Price(priceToUpdate.getPriceId(),
                            pricebook,
                            sku);
            logger.info("price is updated successfully, price={}", savedOrUpdatedPrice);
        } else {
            savedOrUpdatedPrice = priceRepository.save(
                    new Price(pricebook, sku);
            logger.info("price is created successfully, price={}", savedOrUpdatedPrice);
        }

        return Collections.singletonList(savedOrUpdatedPrice);
    }

I'm using a JpaRepository all over the places. Like so..

@Repository
public interface PricebookRepository extends JpaRepository<Pricebook, Long> {}

@Repository
public interface SkuRepository extends JpaRepository<Sku, Long> {}

@Repository
public interface PriceRepository extends JpaRepository<Price, Long> {}