Re: Index scan vs. Seq scan on timestamps - Mailing list pgsql-general

On Mon, 6 Dec 2004, Per Jensen wrote:

> select count(*)
> from accesslog
> where time  between (timeofday()::timestamp - INTERVAL '30 d') and
> timeofday()::timestamp;

Besides the type issue, timeofday() is volatile and thus is not allowed to
be turned into a constant in order to do an index scan because it's
allowed to return different values for every row of the input.