Aurora confused many when first announced at 2014 re:Invent. "MySQL-compatible but not MySQL" — odd phrasing. AWS's message was clear — SQL engine code uses MySQL/PostgreSQL nearly as-is, but the storage, replication, and transaction layers below are redesigned from scratch for cloud. Result: "5x MySQL performance, 3x PostgreSQL + auto-scaling storage + < 1 sec cross-region replication."
In DVA-C02, Aurora appears almost as frequently as RDS but asks differently. RDS asks "managed DB trade-offs," Aurora asks "why is RDS insufficient, when to pick Aurora." Understanding that requires knowing Aurora's storage structure and quorum-based replication. Today we look inside.