Crash resistance

Some writers like duckdb are naturally crash-resistant because writes run inside a transaction.

Other writers are naturally crash-resistant as long as there is only one output table. If there are multiple output tables, you can utilize the anchor_table parameter to implement crash-resistance.

Output tables are written in parallel for performance but the anchor_table is always written last. So you can prune the non-anchor tables at startup from the output database and start from max_block of anchor_table (see restarting from where you left off section)