John Meinel <john@johnmeinel.com> writes:
> As Janning mentioned, sometimes sequential scans *are* faster. If the number of
> entries that will be found is large compared to the number of total entries (I
> don't know the percentages, but probably >30-40%),
Actually 30%-40% is unrealistic. The traditional rule of thumb for the
break-even point was 10%. In POstgres the actual percentage varies based on
how wide the records are and how correlated the location of the records is
with the index. Usually it's between 5%-10% but it can be even lower than that
sometimes.
--
greg
