John Siracusa <siracusa@mindspring.com> writes:
> 1. The query "select max(foo) from bar" where the column foo has an index.
> Aren't indexes ordered? If not, an "ordered index" would be useful in this
> situation so that this query, rather than doing a sequential scan of the
> whole table, would just "ask the index" for the max value and return nearly
> instantly.
http://www.postgresql.org/docs/current/static/functions-aggregate.html
-Neil