1. partitions are never dropped – they got TRUNCATEd (gracefully) during rotation

2. INSERT-only. Each consumer remembers its position – ID of the last event consumed. This pointer shifts independently for each consumer. It's much closer to Kafka than to task queue systems like ActiveMQ or RabbitMQ.

When you run long-running tx with real XID or read-only in REPEATABLE READ (e.g., pg_dump for long time), or logical slot is unused/lagging, this affects performance badly if you have dead tuples accumulated from DELETEs/UPDATEs, but not promptly vacuumed.

PgQue event tables are append-only, and consumers know how to find next batch of events to consume – so xmin horizon block is not affecting, by design.