Perumal Raj <perucinci@xxxxxxxxx> writes: > We have recently upgraded postgres from 9.2 to 11.6 and started seeing > performance issue immediately and able to fix the performance issue after > disabling parameter: enable_seqscan. > Question : > Should i keep the above parameter always disabled ? If not why the behavior > changed in Higher version ? This is unanswerable with the amount of information you've given. Yes, turning off enable_seqscan is a bad idea in general, but why you got a worse plan without that requires details. https://wiki.postgresql.org/wiki/Slow_Query_Questions regards, tom lane