It depends on the use case. For real-time, customer-facing analytics, ClickHouse’s MergeTree engine is a natural fit, so a Postgres → ClickHouse CDC setup with low latencies (single-digit seconds) is better.

Replication to Iceberg/S3 is better suited for offline analytics and data warehousing use cases. You can use the same ClickHouse engine to query layer Iceberg data in S3.