Replication

Active-active replication — where two or more databases accept writes simultaneously and replicate to each other — is one of the most powerful but also most operationally complex GoldenGate topologies. Without a robust conflict detection and resolution (CDR) strategy, you will silently corrupt data on one or both sides. This article covers CDR mechanics, built-in GoldenGate resolution handlers, and architectural patterns that minimise conflict occurrence in the first place. Why Conflicts Occur In a bidirectional topology, any row can be updated on either site concurrently. A conflict occurs when: ...

Oracle GoldenGate is the industry standard for heterogeneous, real-time data replication and change data capture (CDC). Despite being in use for decades, its internal mechanics are frequently misunderstood, leading to poorly tuned deployments that bottleneck at the wrong layer. This article dissects the architecture from the redo log all the way to the target apply. Architecture Overview A GoldenGate pipeline has three logical tiers: Capture — the Extract process mines redo/archive logs on the source database. Distribution — the Data Pump (a secondary Extract) reads local trail files and transmits them to a remote trail on the target host. Apply — the Replicat process reads the remote trail and applies changes to the target database. Each tier operates independently, connected only through trail files — sequential, compressed binary files that serve as a persistent, durable queue between processes. ...