you're correct that duckdb doesn't do any multi-node map-reduce, however duckdb utilizes all available cores on a node quite effectively to parallelize scanning

you're correct that duckdb doesn't do any multi-node map-reduce, however duckdb utilizes all available cores on a node quite effectively to parallelize scanning. And node sizes nowadays get upto 192 vCPUs. A single node can scan through several gigabytes of data per second. When the column data is compressed through various algorithms, this means billions of rows / sec.