"David G. Johnston" <david.g.johnston@xxxxxxxxx> writes: > I'll add that given the nature of the problem that changing temp_file_limit > away from its default of unlimited may be useful. > https://www.postgresql.org/docs/current/runtime-config-resource.html#RUNTIME-CONFIG-RESOURCE-DISK Maybe ... that limits the total space involved, not the number of files it's separated into, so I'm not sure how much it can help. It might be worth playing around to see how varying values of work_mem affect this behavior, too. That should change the planner's initial estimate of the number of hash batches needed, which likely plays into this somehow. regards, tom lane
