Andrew Sullivan wrote:
> > Now, given the choice of the two strategies on a table, both pretty
> > close to one another, the risk of poor performance for using the
> > index scan is minimal based on the statistics, but the risk of poor
> > performance for using the sequential scan is quite high on a large
> > table.
>
> I thought that's what the various cost estimates were there to cover.
> If this is all you're saying, then the feature is already there.
The point is that if the index plan is < 20% more costly than the sequential
scan, it is probably less risky.