Streaming replication in PostgreSQL allows for maintaining a real-time replica of a primary database on standby servers by continuously sending Write-Ahead Log (WAL) records. This minimizes latency and enhances high availability and scalability. Standby servers connect to the primary, request WAL streaming, and apply records to their copies. This process supports synchronous and asynchronous modes, offering flexibility in balancing consistency with performance. Compared to file-based log shipping, streaming replication provides faster failover and lower data loss risks, making it ideal for distributed environments. Understanding WAL output structure and components reveals detailed database operation information.
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