[bladecatcher]

> Now if it were possible for it to accept an event from Kafka but not guarantee that the event will eventually make it into the materialized view but may be lost, that'd be a problem.

This is usually not a problem these days as it’s possible to guarantee exactly once ingestion using Kafka offsets

[missosoup]

IIRC clickhouse still doesn't have this guarantee. It guarantees exactly one ingestion but not that the ingested event gets processed all the way through to view. And if the processing fails, that event won't be retried and is now gone.