Here’s a concise summary of the news article:

Amazon has published a comprehensive report detailing a long-standing issue within PostgreSQL clusters – the “Long Fork” anomaly. This anomaly causes differences in the order that transactions become visible between a primary and its replicas, violating Snapshot Isolation semantics. It’s been recognized since 2013 and doesn’t cause data loss but can lead to unexpected results in applications relying on consistent transaction ordering. While rare in practice due to application-level synchronization, it poses challenges for distributed systems, Aurora DSQL, and Aurora Limitless. AWS is actively working with the PostgreSQL community to address this through a complex patch involving Commit Sequence Numbers (CSNs). The article advises developers to review their application assumptions about transaction ordering and consider explicit synchronization mechanisms if strict ordering is critical.