High-performance Java Persistence Pdf 20 ((hot)) 🌟 📢

High-Performance Java Persistence is a highly regarded book by Vlad Mihalcea, a Java Champion and former Hibernate Developer Advocate. While the original version was published in 2016, it has been continually updated, with recent iterations released as recently as July 18, 2024. Core Focus and Structure

The book is designed to bridge the gap between application development and database administration by focusing on how various Java frameworks interact with relational databases. It is divided into three primary sections:

JDBC and Database Fundamentals: Covers essential performance topics like connection management, batch updates, statement caching, and transaction response times.

JPA and Hibernate: Demonstrates how to use these frameworks efficiently without compromising speed. This includes optimizing basic types, associations, inheritance mappings, and concurrency control.

jOOQ: Explores type-safe querying, common table expressions (CTEs), window functions, and database-specific procedures. Key Performance Strategies high-performance java persistence pdf 20

Mihalcea emphasizes several critical strategies for optimizing the data access layer:

Efficient Querying: Using proper fetch sizes and avoiding the N+1 query problem through strategic fetching.

Connection Sizing: Configuring robust connection pools like HikariCP with optimal maximum pool sizes and timeouts.

Concurrency Control: Understanding locking mechanisms and isolation levels to ensure data consistency under high loads. High-Performance Java Persistence is a highly regarded book

Caching Management: Differentiating between first-level (transaction-scoped) and second-level (cross-transaction) caching to balance speed and data integrity. Current Formats and Availability

The book is available through several official channels, often featuring free PDF access with specific purchases:

Leanpub: Offers the ebook version (PDF, EPUB, MOBI) starting at roughly $34.95; it is updated regularly to include the latest advancements.

Teachable (Downloadable Edition): Provides the ebook as a standalone product for around $24.95 or as part of a larger video course bundle. 2.7 N+1 Query Problem

Amazon: Lists the physical paperback version for approximately $42.99 to $46.12.

GitHub Repository: Mihalcea maintains an open-source repository with code examples that require at least Java 17. High-Performance Java Persistence: Mihalcea, Vlad

Chapter 2 – The PDF Memory Trap

Generating one PDF of 20 MB was fine. But 20 concurrent users → 400 MB heap, plus Hibernate session, plus result sets → GC overhead.

The crash: OutOfMemoryError: Java heap space.

Solution pattern (streaming):

try (Stream<Order> stream = orderRepository.streamByMonth(month)) 
    stream.forEach(order -> 
        pdfBuilder.addRow(order);
        entityManager.detach(order); // prevent memory blow
    );

20.6 Connection Pooling

Properly configuring connection pooling can significantly enhance performance by reusing existing database connections instead of creating new ones.

2.7 N+1 Query Problem