Conclusion

This chapter guides the reader through the fundamental components of high-performance transactional systems. We begin with ACID compliance and its core elements: atomicity of transactions (A), consistency of the database (C), isolation of concurrent sessions and transactions (I), and durability of committed transactions (D).We explore in detail the two most common isolation modes: READ COMMITTED and READ REPEATABLE, illustrating with an extensive example why choosing the correct mode is crucial and how to decide between them.Additionally, we review key programming constructs for transactions, such as BEGIN TRANSACTION, COMMIT TRANSACTION, ROLLBACK, and SAVEPOINT, and demonstrate how developers can implement and manage transactions, isolation levels, and locks in Postgres.The chapter wraps up with a detailed discussion of database normalization and the use of slowly changing dimensions. In these sections, we walk the reader through each step of developing the product reference...