Andrew Snow writes:
> Since it can get the answer straight out of the index, and if there are
> potentially numerous rows, looking up a b-tree is faster than a linear
> search?
You can't get the "answer straight out of the index". You always need to
check back in the real table to see whether the row is visible to your
transaction.
--
Peter Eisentraut peter_e@gmx.net http://funkturm.homeip.net/~peter