Re: inconsistent/weird index usage

On R, 2004-10-01 at 19:34, Tom Lane wrote:
> Josh Berkus <josh@agliodbs.com> writes:
> >> Most of the problem here comes from the fact that "current_date - 7"
> >> isn't reducible to a constant and so the planner is making bad guesses
> >> about how much of each table will be scanned.
>
> > I thought this was fixed in 7.4.  No?
>
> No.  It's not fixed as of CVS tip either, although there was some talk
> of doing something in time for 8.0.

That's weird - my 7.4.2 databases did not consider (now()-'15
min'::interval) to be a constant whereas 7.4.5 does (i.e. it does use
index scan on index on datetime column)

Is this somehow different for date types ?

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Hannu