Tom Lane wrote:
>Au contraire --- a full-table index scan can be vastly slower than a
>full-table seqscan. I think it's wishful thinking to assume that
>picking an indexscan is the right thing when we don't know any better.
>
>
>
I wish we could get this basic truth across to users somehow - I have
lost count of the number of times I have had to explain that the
crossover in cost between a sequential scan and an index scan occurs at
a surprisingly low proportion of a table in most cases.
cheers
andrew