Great question! Improving the speed of writing updates to DuckDB has been a significant focus for us. Early in the project, we identified that DuckDB is quite slow for single-row writes, as discussed in this issue: https://github.com/apecloud/myduckserver/issues/55

To address this, we implemented an Arrow-based columnar buffer that accumulates updates from the primary server. This buffer is flushed into DuckDB at fixed intervals (currently every 200ms) or when it exceeds a certain size threshold. This approach significantly reduces DuckDB's write overhead.

Additionally, we developed dedicated replication message parsers that write directly to the Arrow buffer, minimizing allocations.

A community contributor has validated & enhanced the effectiveness of our approach: https://github.com/apecloud/myduckserver/pull/207

We plan to publish benchmarks on replication latency and query performance in the coming weeks. Stay tuned!