"Steinar H. Gunderson" <sgunderson(at)bigfoot(dot)com> writes:
> To me, it looks like he'll get 88 rows, not 3.2M. Surely we must be able to
> do something better than a full sequential scan in this case?
Not really. There's been some speculation about implementing index
"skip search" --- once you've verified there's at least one visible
row of a given index value, tell the index to skip to the next different
value instead of handing back any of the remaining entries of the
current value. But it'd be a lot of work and AFAICS not useful for
very many kinds of queries besides this.
regards, tom lane