Matthew Wakeling <matthew@flymine.org> writes:
> It is certainly doing a sequential scan. So are you saying that it will
> start a sequential scan from a different part of the table each time, even
> in the absence of other simultaneous sequential scans?
Yeah, that's the syncscan logic biting you. You can turn it off if you
want.
> Some trivial testing with "select * from location limit 10;" indicates
> that it starts the sequential scan in the same place each time - but is
> this different from the above query?
Yup, you're not scanning enough of the table to move the syncscan start
pointer.
regards, tom lane