On Fri, 2021-02-19 at 11:21 +0100, Luca Ferrari wrote: > > At execution time, PostgreSQL will use as many of the planned workers > > as are currently available (max_parallel_workers). > > Thanks, but just to make it clear, assuming I execute almost > simultanously two identical queries that can be therefore be > parallelized, does that mean that the first one will be executed with > the max available parallele capacity and the second will "starve" on > parllelism being executed sequentially. Is this correct? > As a consequence to that, this also could mean that a query over a > small table could take more advanatge (in parallel sense) than a scan > on a larger table that was issued just a moment after (assuming both > table can be scanned in parallel), right? Precisely. That is why you have "max_parallel_workers_per_gather" to limit the number of parallel workers available to a single query. Yours, Laurenz Albe -- Cybertec | https://www.cybertec-postgresql.com
