"Logical-Replication"
- PostgreSQL Replication Slot Management：Physical / Logical / Failover Slot 治理
PG replication slot 是 *primary 端的 standby 進度紀錄*、防 WAL premature deletion。但 orphan slot 會吃 disk、failover 後 logical slot 不會自動跟新 primary、是 PG 操作的 hidden complexity。本文走 physical / logical slot 差異、slot lifecycle、failover slot synchronization（PG 17+ 新特性）、orphan slot 治理、5 production 踩雷（orphan slot disk 爆 / logical slot lag / failover 後 slot 丟 / wal_keep_size 跟 slot 衝突 / connection 同時打 slot 數量限制）
- PostgreSQL Logical Replication + Debezium CDC：replication slot × failure × recovery 對照
PostgreSQL logical replication slot 跟 Debezium CDC 的失效模式對照表：slot lag 撐爆 primary disk / schema change 斷流 / 初始 COPY 鎖表 / zombie slot 不釋放 / replay storm 後 offset reset；publication / subscription / pgoutput 配置、跟 Kafka outbox pattern 整合