Zero-Downtime

Upgrading PostgreSQL across major versions (e.g., from v12 to v16/v17) is a critical operational task for database administrators. Major releases introduce system catalog changes, binary format modifications, and performance enhancements that require full database engine reinitialization. Traditionally, DBAs relied on in-place upgrades using pg_upgrade. While pg_upgrade in --link mode is fast, it still requires shutting down the primary database engine, incurring mandatory do