Capturing Data Changes - Part 2: Write-Ahead Log shipping and Trigger-based approaches

This video dives into the lower-level techniques for replicating data changes. Learn how Write-Ahead Log (WAL) records and trigger mechanisms capture granular updates for reliable replication in systems like Postgres. Timeline: • 00:00 WAL Replication Overview – Introduction to low-level replication via WAL. • 05:21 Storage Layout & Write-Ahead Log in Postgres – Understanding how data storage and WAL work together.   – Concept of Write-Ahead Log: Why WAL is essential for durability.   – Internal Layout of Pages & XLog Records: The structure behind WAL records. • 17:51 WAL-Based Replication in Postgres – How WAL records are streamed from primary to standby systems. • 20:29 Trigger-Based Replication – Capturing changes using database triggers for external processing. • 27:02 Summary & References – Wrap-up of key insights and additional resources. The video is based on my article https://fedianin.com/2025/02/14/database-replication-streams-from-statementbasedtowal/