My initial response that changing the parameter worked was mistaken. I forgot to shut down version 16 so the function call happened on that instance. I now shut down 16, fired up 17 and set the parameter, and the behavior did not change. The query itself returns results in about 1 second. The function never returns at all, it just sits there.
Lowell Hought <lowell.hought@gmail.com> writes: > Yes! I just changed the parameter as you suggested and the query returned > as expected. > So I guess something changed between version 16 and version 17? Perhaps > the default for that setting?
No, that default has not changed. What apparently happened is that cost estimates or something changed enough to persuade the planner to use a generic plan that's considerably inferior to what it was choosing before. There's nowhere near enough info in your report to pin it down more closely than that.
Just to eliminate the obvious --- you did run ANALYZE after the upgrade, right? If you had any nondefault settings of default_statistics_target or similar planner parameters, did you make sure they got transferred to the new installation?
