Jeffrey Tenny <jeffrey.tenny@comcast.net> writes:
> I tried the seqscan disabling and got what sounds like the desired plan:
> Sort (cost=54900.62..54940.29 rows=1587 width=16) (actual time=20.208..22.138 rows=677 loops=1)
> Sort Key: f, c
> -> Index Scan using x_f_idx, x_f_idx, ...
> (cost=0.00..54056.96 rows=1587 width=16) (actual time=1.048..15.598 rows=677 loops=1)
> Index Cond: ((f = 1) OR (f = 2) OR (f = 3) ....
Hm, vs 35000 or so estimates for the slower plans. My recommendation
would be to decrease random_page_cost to 2 or so, instead of the brute
force disable-seqscans approach.
regards, tom lane