I have a JdbcCursorItemReader reader that needs data from another Postgres database. The data from the Postgres database is to be used to enrich the Products with additional data. How do I arrange this so I can only read the data that is needed to enrich the data that has been read for the products. I have a fetchSize of 200 for the JdbcCursorItemReader, however the ItemProcessor interface only takes a single product. It appears that the only way is to read all the product enrichment data all at once so I can use that to look up corresponding productId from the Postgres database. Is rhere another way? How do I incorporate the product detail? I do not want to read the product detail product by product but it seems to only way.

        import lombok.RequiredArgsConstructor;
        import org.springframework.batch.core.Step;
        import org.springframework.batch.core.repository.JobRepository;
        import org.springframework.batch.core.step.builder.StepBuilder;
        import org.springframework.beans.factory.annotation.Qualifier;
        import org.springframework.beans.factory.annotation.Value;
        import org.springframework.context.annotation.Bean;
        import org.springframework.stereotype.Component;
        import org.springframework.transaction.PlatformTransactionManager;
        
        @Component("updateProductsStep")
        @RequiredArgsConstructor
        public class UpdateProductItemsStep {
        
            @Value("${processing.chunk-size}")
            private int chunkSize;
        
            private final JobRepository jobRepository;
        
            private final PlatformTransactionManager platformTransactionManager;
        
            @Qualifier("productValidatorItemProcessor")
            private final ProductValidatingItemProcessor productValidatorItemProcessor;
        
            @Qualifier("productReader")
            private final ProductJdbcCursorReader productJdbcCursorReader;
        
            @Qualifier("productUpdateWriter")
            private final ProductUpdateWriter productUpdateWriter;
            
            //This is the missing part to add - This reads from PostGres
            @Qualifier("productDetailReader")
            private final ProductDetailReader productDetailReader;
        
        
            @Bean("updateProductInitialLoadingStep")
            public Step updateProductInitialStep(){
                return new StepBuilder("ProductLoaderStep",jobRepository)
                        .<Product, Product>chunk(chunkSize,platformTransactionManager)
                        .reader(productJdbcCursorReader)
                        .processor(productValidatorItemProcessor)
                        .writer(productUpdateWriter)
                        .build();
            }
        }

How can I add a step to add the extra detail to the Products after they have been read