On Mon, 4 May 2020 at 15:52, Arya F <arya6000@xxxxxxxxx> wrote: > > On Sun, May 3, 2020 at 11:46 PM Michael Lewis <mlewis@xxxxxxxxxxx> wrote: > > > > What kinds of storage (ssd or old 5400 rpm)? What else is this machine running? > > Not an SSD, but an old 1TB 7200 RPM HDD > > > What configs have been customized such as work_mem or random_page_cost? > > work_mem = 2403kB > random_page_cost = 1.1 How long does it take if you first do: SET enable_nestloop TO off; If you find it's faster then you most likely have random_page_cost set unrealistically low. In fact, I'd say it's very unlikely that a nested loop join will be a win in this case when random pages must be read from a mechanical disk, but by all means, try disabling it with the above command and see for yourself. If you set random_page_cost so low to solve some other performance problem, then you may wish to look at the effective_cache_size setting. Having that set to something realistic should allow indexes to be used more in situations where they're likely to not require as much random I/O from the disk. David
