Backend Engineering #7.2 SQL, Indexing, JPA, Hibernate & Database Locking

In this session, we continue the Data & Persistence module and go deeper into how databases and Java backend applications actually work together in real-world systems. We cover: • SQL Execution Order - FROM/JOIN, WHERE, GROUP BY, HAVING, SELECT & ORDER BY • Database Indexing & B-Tree Indexes • Leftmost-Prefix Rule & Index Performance • ACID Properties & Database Transactions • JPA & Hibernate - How Java Entities Map to Database Tables • JPA Dirty Checking & Automatic Database Updates • N+1 Query Problem & JOIN FETCH • Optimistic Locking using @Version • Pessimistic Locking using FOR UPDATE • Real-World PostgreSQL Row Locking Demo with Concurrent Transactions • spring.jpa.open-in-view=false & Production Considerations • Spring Transaction Proxy & Self-Invocation Problem We focus on understanding what actually happens behind JPA and Hibernate - from Java entity operations to the SQL queries executed against the database. We also practically demonstrate database locking using two concurrent PostgreSQL sessions to understand how race conditions occur and how row-level locking prevents conflicting updates. This is Part 2 of the Data & Persistence module. Notes Link: https://drive.google.com/file/d/1bp0h... Want to join the free live class? Visit here: https://forms.gle/GwkkbGQ7typfBy9A8 Part 1 → Database Fundamentals & ERD | DBMS, RDBMS #SpringBoot #JavaBackend #BackendDevelopment #JPA #Hibernate #PostgreSQL #SQL #DatabaseIndexing #DatabaseLocking #Database #Transactions #BackendEngineering #JavaDeveloper #SoftwareEngineering #EngineerAnna