Ken Geis wrote:
> I went through the code (7.4 beta2) that estimates the cost of an index
> scan path. What I need to be sure of is that when running a query in
> pgsql that uses only the columns that are in an index, the underlying
> table need not be accessed. I know that Oracle does this.
Thinking about it some more, it's obvious to me that a pgsql index scan
must be accessing the underlying table even though all of the
information needed is in the index itself. A linear scan of a 660M file
should not take 55 minutes. I could confirm this with stats, but
someone out there probably already knows the answer here.
Ken